Castles in Normandy: Five Strongholds Between the Sea and the Vexin

By StoneKeep Atlas · Published September 2, 2026 · Last updated September 14, 2026 · Editorial standards

The castles in Normandy are the architecture of a frontier that kept moving. In 1066 a duke of Normandy crossed the Channel and was crowned king of England, and from then until 1204 his successors ruled on both sides of the water while defending, at home, the land border they had left behind. That border ran down a small river, the Epte, east of Rouen. What holding it left standing is gathered in this guide: the ducal birthplace at Falaise, the ducal capital at Caen, the fortress Richard I of England raised on the Seine between 1196 and 1198, the frontier lock at Gisors, and, at the far western end of the duchy, the abbey the sea defended on Mont-Saint-Michel. In 1204 the border closed over every one of them.

This is the Normandy section of our national pillar on the châteaux of France, and it is deliberately a short roster. Five fortified sites, from the bay to the Vexin, chosen because together they are the frontier and the sea end to end, and each already has a full guide of its own on this site. What this page adds is the part no single guide can: how the five compare, what each was built to do, why these and not others, and how to drive between them in the right order.

A word on what you will find when you arrive. None of the five is a reconstruction, and none of them is untouched: at Caen the great hall was restored in 1962 and the keep is a footprint; at Falaise a ten-year campaign put roofs and floors back and signed its work in concrete; Château Gaillard and Gisors are ruins the national register grades vestiges; and the abbey on Mont-Saint-Michel wears a spire put up in 1897. Each guide says so at length. Here the point is the pattern: a Norman castle is usually a medieval plan with later hands all over it.

The Five at a Glance

Read the table as a description of what stands today, not as a ranking, and read its wording as the sources’ own. The national register titles Gisors “Restes du château” and grades both Gisors and Château Gaillard as vestiges, while its condition field is simply empty for the other three, which is not a grade of good. Every cell is a durable fact. Prices, opening hours and season dates change, and they live only in each guide’s own Admission table, which is where to check before you set out. Two things the table cannot show follow below: what each site was built to do, and how the five sit on a map that runs from the bay of Mont-Saint-Michel to the edge of the Vexin.

A Frontier That Kept Moving

Normandy’s story as a castle landscape begins with a duchy that faced two ways. Its dukes held their land from the king of France, and in 966 one of them, Duke Richard I of Normandy, installed Benedictine monks on the rock in the bay that would become Mont-Saint-Michel. A century later the duchy produced a duke who wanted more. Duke William founded the castle at Caen about 1060, and the city’s own museum puts the foundation in its proper light: the will of William, Duke of Normandy, on the eve of the conquest of England. He was the future king of England, not yet a king, and the distinction matters on every date that follows. Duke William was crowned king on 25 December 1066, and from that day the ruler of Normandy had a kingdom across the sea and a land border at home.

That border was the problem. It ran, in the east, along the Epte, a modest river between Rouen and Paris, and the operator of the castle at Gisors describes it as the natural limit between the two kingdoms and the town’s natural ditch. Gisors was begun in 1097, in the reign of William Rufus, as an earth motte with ditches carrying what was probably a timber tower behind a palisade. The Ville de Gisors calls the castle the eastern lock of Normandy, one item in a campaign of fortification along the Epte, and that phrase, verrou oriental, is the frontier thesis in an operator’s own words. Meanwhile the dynasty’s building at home went on. Henry I Beauclerc was king of England from 1100 and duke of Normandy after Tinchebray in 1106. As ruler of the duchy, he raised the stone keep and the Salle de l’Échiquier at Caen about 1120 and the great tower at Falaise about 1123. Under Henry II Plantagenet, king of England and duke of Normandy, a second campaign of works followed at Gisors, and the commune credits it with the great outer enceinte that wraps the octagonal great tower. The wider arc of that century, and how the Normans exported the castle itself, is told in our history of castles.

The end came from the east, and it came in stages. Philip II of France, known as Philip Augustus, took Gisors in 1193, eleven years before the duchy itself went. The response was Château Gaillard. Richard I, king of England and duke of Normandy and known as the Lionheart, raised it between 1196 and 1198 to hold the Seine and the approach to Rouen against Philip II of France. The Ville des Andelys calls it built “in record time”, and the town’s own leaflet has Richard building it to protect his Anglo-Norman duchy. Nobody should be more precise about those two years than the sources are. F. M. Powicke, who printed the surviving Norman Exchequer account for the works, warned in a footnote that the chronology of 1197 to 1198 is “hopelessly involved and can only occasionally be tested by official documents”, so this guide gives the two dates and no chronology between them.

Then the sequence, and only the sequence. The French armies came before Château Gaillard in September 1203, and it surrendered on 6 March 1204. In the same year Normandy passed to the French crown, the Channel Islands excepted; Caen and Falaise passed to Philip by surrender in May of that year. Nothing here says the one caused the other, because the sources do not. What they do say is that a border which had been a river for a hundred years stopped being a border at all, and the castles built to hold it became, overnight, castles inside France. The Angevin lands the same dynasty held south of Normandy have their own end, told in our guide to Château de Chinon.

What Each of the Five Was For

Start with the one scholarly sentence that puts these buildings in a single frame. Reviewing Michel de Boüard’s excavation report in the Bulletin Monumental in 1979, Jean Mesqui opened by placing Normandy’s castles in a national setting. The region, he wrote, “compte certains des plus beaux et plus vastes sites fortifiés qui subsistent en France”: among the most extensive fortified sites surviving in France, and, he thought, among the handsomest. Mesqui named Gisors, Château-Gaillard and Falaise among them, “parmi d’autres”, before adding Caen. Four limits ride with that sentence, and this guide keeps every one of them. It is membership, not rank: some of the most extensive, never the largest. It is sites, not castles: the word covers an enclosure as easily as a tower. It is what survives, which makes it a claim about 1979 rather than about the Middle Ages. And it is France, never Europe.

Size is where the temptation to widen begins, so here is the one size claim the page makes. Caen’s rampart runs more than eight hundred meters around roughly five hectares, and the city calls it “one of the largest fortified enclosures in Europe”, crediting that extent not to William but to his Anglo-Norman successors, the dukes of Normandy who were also kings of England. Set that beside Falaise, whose enclosure is the operator’s about 1.5 hectares, and the point of the roster is clear: these five are not a size class. They are five different jobs.

Mesqui gives a comparison class and says nothing about what any of them was for, so the jobs come from the operators and the register, in the past tense. Mont-Saint-Michel was a monastery the duchy also used as a fortress, a description its operator scopes to the Middle Ages. Falaise was the ducal birthplace, and its surviving keep is one the operator calls a typically Anglo-Norman fortress. Caen was the seat of a ruling duke, and then a favorite residence of dukes who were also kings. Château Gaillard was built to hold the Seine and to cover Rouen. Gisors was the frontier lock, the eastern bolt of Normandy in the commune’s own phrase. One monastery, one birthplace, one capital, one river fortress, one border post: that is the whole argument for treating them together, and it is why a sixth would be a different argument rather than a longer list.

The buildings answer to those jobs in ways our reference articles explain in general. Two of the roster’s great towers, Henry I’s at Falaise and the massive octagonal one on the motte at Gisors, are the Anglo-Norman keep in its two commonest shapes. How such towers were meant to work is the subject of our reference on castle keeps. The round towers that came after 1204 mark the change of hands in stone: the cylindrical keep at Falaise of about 1207 that the site calls the Tour Talbot, and the circular Tour du Prisonnier at Gisors, built on the model of the keep of the Louvre. Their geometry is in castle towers and turrets. Caen is easiest to read through its vocabulary: an enceinte with a chemise, the stone ring wrapped closely around a keep, a term our reference on the parts of a medieval castle defines. And Château Gaillard, with its enclosures set in series along the neck of a spur so that each had to be taken in turn, is the roster’s clearest lesson in how castle defenses worked.

Mont-Saint-Michel: The Site the Sea Defended

Mont-Saint-Michel is the site on this page that never stopped working: a dozen monks and nuns live in the abbey today, and the walled town below it is classified in its own right, with its ramparts separately classified in the national register and protected as State property. The abbey has been a classified historic monument since the list of 1862, and the town’s ramparts since 1875. In 966 Duke Richard I of Normandy installed Benedictine monks on the rock, and he is not the Richard I of England who built Château Gaillard. Work on the Romanesque abbey church began, in the operator’s own hedge, “according to tradition in 1023”.

Call it what its operator calls it. The Centre des monuments nationaux describes the abbey as a fortress of the duchy of Normandy during the Middle Ages, and that scoping is exact: this is a fortified abbey, not a castle. It earns its place here as the sea end of the frontier. The Mount held out through the Hundred Years War, and the operator credits its ramparts and its tides. On the culture ministry’s count the abbey drew about 1.5 million admissions in 2024, a figure for the monument itself and not for the island around it. Our full guide to Mont-Saint-Michel takes the abbey level by level and explains the tides, the walk up, and what the village below adds.

Château de Falaise: The Ducal Birthplace

Falaise is the castle the national monuments record calls William’s château natal, his birthplace, in an entry six words long that claims nothing about a room, a date or a building. Its oldest standing building is Henry I’s great tower of about 1123, raised on the site of an earlier castle; only faint traces of William’s own keep remain. The operator calls that great tower, its Grand Donjon, a typically Anglo-Norman fortress. The second of the three keeps is the Petit Donjon, which the site furnishes as a twelfth-century princely interior, and the third is the cylindrical Tour Talbot, put up about 1207, after the duchy had passed to the French crown.

A ten-year campaign between 1986 and 1996 re-roofed and re-floored the keeps, and it made no attempt to hide itself. The forebuilding a visitor climbs to enter is dark gray concrete of 1996, restoring volumes the archaeology could only hypothesize. The enclosure is the operator’s about 1.5 hectares on a rock above the town, and its ditches were dry by design and progressively filled in the eighteenth century. Walking into the enclosure costs nothing; the ticket buys the keeps, and the operator states that they cannot be visited in a wheelchair or with a stroller. Our guide to Château de Falaise walks the three keeps in order and separates what is twelfth-century from what is 1996.

Château de Caen: The Ducal Capital

Caen is an enclosure rather than a building: more than eight hundred meters of restored rampart around roughly five hectares, with two museums inside it, the Musée de Normandie and the Musée des Beaux-Arts. As first built, about 1060, the castle was a single large stone enclosure with no flanking towers, crowning the Darnetal spur, entered from the north through a rectangular gate-tower whose footings the excavators recovered. Nothing of the great tower stands. Its footprint is read from a belvedere, and so are the foundations of the chemise with four round towers that was thrown around it under Philip II; the Musée de Normandie says the historical documentation and the archaeology do not allow a reconstruction of the lost building to be proposed.

The one great interior that survives, the Salle de l’Échiquier, was restored in 1962: the walls are Romanesque, the upper windows are reconstituted, and the tiled floor is an interpretation of a late state of a floor that was beaten earth in the twelfth century. After the Revolution the keep was leveled, the ditches filled and the site handed to the army, which is why a visitor today walks a park rather than a castle. Three parts of it are free to enter: the park, the church of Saint-Georges and the Salle de l’Échiquier; the museums are ticketed. For the excavated keep, the hall, the two museums and what the city did with the walls after 1944, see our guide to Château de Caen.

Château Gaillard: The Fortress on the Seine

Château Gaillard is a ruin, and the ruin is not the siege. The fortress Philip took in 1204 stood for four more centuries. In 1598 the provincial estates of Normandy asked Henri IV to pull it down; it was quarried for stone from 1603, and the dismantling finished in 1611. What is left is graded vestiges in the national register: the circular keep with its projecting spur, and enclosures that run in series along the neck of the spur rather than one inside another. It dominates the Seine without being on the summit of the small hill behind it, and that higher ground is where Philip’s covered way came down.

Ownership is split, and the register says so. The State’s share is limited to the keep and its chemise; the commune and private owners hold the rest, with the Ville des Andelys as the visitor-facing operator. The outer works are open freely all year, and the upper enclosure is ticketed across a season. What you will not read here is anything about the interior of the keep, because its status is the operator’s to announce. Our guide to Château Gaillard reconstructs the siege of 1203-1204 from the sources, explains why the site was chosen, and tells the story of the friars who carried it away.

Château de Gisors: The Frontier Itself

The national register titles Gisors “Restes du château” and grades it vestiges, which is a fairer description than any adjective would be. What stands is the frontier in three layers. The motte of 1097 sits inside its dry ditches, and on it stands the massive octagonal great tower, raised in the first half of the twelfth century inside the stone ring the operator calls a chemise. Across the park stands a second great tower, this one circular: the Tour du Prisonnier, put up after Philip II took the place in 1193, on the model of the keep of the Louvre. The commune puts the outer enceinte at more than eight hundred meters with eight towers.

Keep the two waters apart here. The Epte was the town’s natural ditch and the border with the French king; the castle’s own ditches are dry, and always were. Since the Revolution the castle has belonged to the commune, and the arrangement today follows from that. Access to the park is free. The octagonal great tower on its motte, the circular great tower called the Tour du Prisonnier and the Tour Saint-Thomas are entered on a guided visit in French only, in season, and the operator times that visit at an hour and a half. Children under six cannot join it, which the commune gives as a safety rule. Our guide to Château de Gisors reads the prisoners’ carvings and follows the 1097 motte through its stone phases; it also deals with the treasure legend once and for all.

Why These Five, and Why Not Rouen or Brittany

A short roster has to defend its edges. These five are the frontier and the sea end to end: the ducal birthplace, the ducal capital, the fortress Richard raised on the Seine between 1196 and 1198, the Epte frontier itself, and the site the tide defended. Add a sixth and the argument changes, so a sixth is a rewrite decision rather than an extension. Ask the regional tourist board a different question and it arrives at nearly the same list. Its own grouping of medieval military architecture from the time of the duke-kings names “les châteaux forts de Caen et Falaise, Château-Gaillard aux Andelys, Gisors, ou Harcourt”, four of the five here, plus Harcourt.

Rouen is the obvious absence, and the reason is what survives. Rouen’s castle is a single tower, the only remaining vestige of the fortress, as its operator says, and the national register records it as the tower in which Joan of Arc was interrogated. One tower in a city whose draw is elsewhere is a stop on a Rouen day, not a member of this roster.

Brittany is the second absence. Mérimée’s own regional field separates Normandie from Bretagne, and Fougères, Vitré and the Château des Ducs de Bretagne are Breton notices; this guide does not annex a neighbor to reach five. And the 1944 landing sites are the region’s other great subject, filed apart from its heritage on Normandy’s own tourist-board site as of 2026; they are not on this page.

Seeing Them in One Trip

Mont-Saint-Michel to Gisors is about 310 km of road, and calling at all five in order is nearer 390 km and close to five hours behind the wheel before you stop anywhere; drive figures on this page are our own measurement, computed with openrouteservice. Three days is the honest shape: Château Gaillard and Gisors are under forty minutes apart and make one day, Caen and Falaise another, and Mont-Saint-Michel takes a day of its own. Château Gaillard comes before Gisors, because taking Gisors first costs about half an hour and 30 km on an otherwise identical trip. Which start days actually work is a separate question, and it turns on closures rather than on distances. Our Normandy castles itinerary sets out the order, the legs and where the nights go.

Tickets follow one pattern five times over, and no single guide can state it: each of the five lets you in somewhere for nothing and charges for the core. At Caen, Château Gaillard, Gisors and Falaise the outer enclosure or lower court is free and the inner works are ticketed; Falaise’s own rules put its basse-cour in free access and the entry charge on the keeps. Mont-Saint-Michel is a free village under a ticketed abbey, and the operator asks you to allow three quarters of an hour to an hour to walk up from the car parks, which is why the Mount is a day rather than a stop; free shuttles run from the car parks to the Mont and take the flat part of that distance out of the walk. Falaise is open all year, with an occasional Monday closure and a winter closure of several weeks. Château Gaillard and Gisors are the two that open their ticketed parts only across a spring-to-autumn season, and neither operator’s own page gives a reason; Gaillard’s upper court is closed on Mondays and Tuesdays within that season. Come outside it and both are still worth the stop, because at Gaillard the outer works and at Gisors the park stay open and free.

By rail the five do not divide neatly. Caen and Gisors each stand in a town with its own passenger station. Mont-Saint-Michel’s is Pontorson-Mont-Saint-Michel and Château Gaillard’s is Gaillon-Aubevoye, and neither of those two is at the site: both leave a road leg at the end. Falaise has no railway station; the usual rail approach is Caen and a regional coach, and Caen is named for the coach connection rather than for proximity. The station names are SNCF’s own.

None of the five is an easy site for a wheelchair. Four sit on rock or a motte and their operators say so plainly: at Mont-Saint-Michel the abbey is at the top of the rock up a great many steps, and its operator calls the site difficult to access for visitors with reduced mobility and for strollers. At Falaise the operator states the keeps cannot be visited in a wheelchair or with a stroller. Château Gaillard is not accessible, and the free lower works are not an easier alternative, because the gradient is on the path both share. At Gisors the gardens are accessible. Caen is the exception, and the exception is the museum rather than the castle: its reception spaces are accessible, a lift serves the Logis des Gouverneurs, and a wheelchair is lent at the desk subject to availability.

If you would rather not drive every leg, GetYourGuide lists guided tours and tickets across Normandy, and for somewhere to sleep Booking.com covers the whole region, with Caen the town the arithmetic above points to.

Some links on this page are affiliate links, which means StoneKeep Atlas may earn a small commission, at no extra cost to you, if you book through them.

Common Questions

Are there any castles in Normandy?

The culture ministry’s register of protected monuments lists 3,116 in Normandy, of which 477 are denominated a château or a château fort: 128 in Calvados, 94 in Seine-Maritime, 92 in the Eure, 85 in the Manche and 78 in the Orne. That counts listed notices rather than buildings, and the French word covers the country house as well as the fortress, which is the problem behind national castle counts. The region’s own tourist board takes a different question and lists about 140 châteaux and manors you can actually visit.

Are any of the Norman castles still standing today?

Answering for Normandy itself, since that is where the question is asked: yes, in four different states. Mont-Saint-Michel is inhabited; Falaise is a medieval shell around a 1986-96 intervention; Caen is an enclosure whose keep is a footprint; only Gisors and Château Gaillard carry the register’s vestiges grade. For the other three the register’s condition field is simply empty, and an empty field is not a grade of good.

Which castle was William the Conqueror’s?

Three places answer, and what stands at each is the point. Falaise is his château natal in the national register; the year is not settled, the operator gives none, and the sources that do give 1027 or 1028. Caen castle he founded about 1060, as duke, and nothing of its great tower stands. He also founded the Abbaye aux Hommes there, and its church is where he was buried after his death in September 1087. At neither castle does anything he raised still stand to its full height. The one building of William’s that does is that abbey church, which the register dates to the second half of the eleventh century and to the three centuries after it.

Is there a castle in Normandy surrounded by water?

Not on this page, and the premise is the interesting part. A moat is a water-filled ditch; a dry ditch is a ditch, and three different things are true of the five. Gisors, Falaise and Château Gaillard have dry ditches by design, and Gaillard’s are three, quarried straight down out of the chalk on a spur above the Seine where there was never any way to flood them. Caen’s were filled after the Revolution, and its protection order expressly excludes them. And the Mount is surrounded by the sea, which is a tide and not a moat.

Can you see the Normandy castles in one trip, and how long does it take?

Yes, and the honest shape is three days. The road from Mont-Saint-Michel to Gisors is about 310 km; a route that calls at all five is nearer 390 km, close to five hours of driving with no stops in it. Those are our own openrouteservice measurements, door to door. Three groups fall out of the map: Caen with Falaise, Château Gaillard with Gisors in that order, and the Mount on a day of its own. Which start days actually work is a separate question, and our Normandy castles itinerary sets the route out day by day.

What is the difference between a Norman castle and a castle in Normandy?

Not much; the difference is habit rather than substance. The Getty’s Art & Architecture Thesaurus files “Norman” under French Medieval styles: the culture that emerged in northern France in the tenth and eleventh centuries and expanded from Normandy to the British Isles, southern Italy and Sicily. Normandy is where the label starts. English readers meet it mostly on buildings put up in England after 1066, and Historic England’s period thesaurus dates its Medieval period from “the Norman invasion (1066)”; that is where the word traveled, not where it belongs.

Beyond Normandy

This roster is one region of a national picture. Our national guide to the châteaux of France places Normandy beside the Loire, Provence and the rest. The dynasty whose border this page follows held lands far to the south, and their story ends in our guide to the castle at Chinon. Two reference pieces reach into this roster from the other direction. Caen’s Salle de l’Échiquier belongs to the story of the great hall and medieval castle life, and the question of how castle counts are made, which the first of the questions above turns on, is the subject of which country has the most castles.

Conclusion

What holds this roster together is a border, not a style. A duchy that had conquered a kingdom spent the next century and more fortifying the line it had left behind at home, from the Epte to the bay, and in 1204 that line closed over the whole of it. Read the buildings in that order and each one explains the next: a birthplace, a capital, a river fortress built against a king its builder owed homage to, a lock on the frontier, and an abbey the tide guarded. None of them survives as it was built, and the honest guides say so. Plan the drive from east to west or west to east, keep Château Gaillard before Gisors, give the Mount its own day, and let the guides linked above carry the prices, the hours and the detail.

Principal Sources

• Centre des monuments nationaux. “History of the monument.” abbaye-mont-saint-michel.fr.
• Centre des monuments nationaux. “Practical information.” abbaye-mont-saint-michel.fr.
• Centre des monuments nationaux. “S’orienter dans le monument.” abbaye-mont-saint-michel.fr.
• Château Guillaume-le-Conquérant, Falaise. “Son histoire.” chateau-guillaume-leconquerant.fr.
• Château Guillaume-le-Conquérant, Falaise. “Seul, en famille ou entre amis.” chateau-guillaume-leconquerant.fr.
• Château Guillaume-le-Conquérant, Falaise. Dossier de presse. chateau-guillaume-leconquerant.fr.
• Château Guillaume-le-Conquérant, Falaise. Règlement intérieur. chateau-guillaume-leconquerant.fr.
• Château Guillaume-le-Conquérant, Falaise. “Sa restauration.” chateau-guillaume-leconquerant.fr.
• Getty Research Institute. Art & Architecture Thesaurus, “Norman,” ID 300020851. getty.edu.
• Historic England. Periods thesaurus, scope note for “Medieval.” heritagedata.org.
• Le Donjon de Rouen. “Histoire.” donjonderouen.com.
• Mesqui, Jean. Review of Michel de Boüard, Le château de Caen. Bulletin Monumental 137-3 (1979): 267-268. persee.fr.
• Ministère de la Culture. “Abbaye et dépendances, Le Mont-Saint-Michel.” Base Mérimée, notice PA00110460. pop.culture.gouv.fr.
• Ministère de la Culture. “Ancienne abbaye aux Hommes, Caen.” Base Mérimée, notice PA00111124. pop.culture.gouv.fr.
• Ministère de la Culture. “Remparts, enceinte de la ville et ses dépendances, Le Mont-Saint-Michel.” Base Mérimée, notice PA00110514. pop.culture.gouv.fr.
• Ministère de la Culture. “Château, actuellement musées de Caen.” Base Mérimée, notice PA00111127. pop.culture.gouv.fr.
• Ministère de la Culture. “Château fort, actuellement collège, Falaise.” Base Mérimée, notice PA00111309. pop.culture.gouv.fr.
• Ministère de la Culture. “Château-Gaillard, Les Andelys.” Base Mérimée, notice PA00099304. pop.culture.gouv.fr.
• Ministère de la Culture. “Restes du château, Gisors.” Base Mérimée, notice PA00099430. pop.culture.gouv.fr.
• Ministère de la Culture. “Château fort, collège, Falaise.” Inventaire général, notice IA00000989. pop.culture.gouv.fr.
• Ministère de la Culture. “Tour dite de Jeanne d’Arc ou ancien donjon du château de Philippe-Auguste, Rouen.” Base Mérimée, notice PA00101011. pop.culture.gouv.fr.
• Ministère de la Culture. Base Mérimée, open-data export (merimee.csv), read 1 September 2026. POP open data.
• Ministère de la Culture, Département des études, de la prospective et des statistiques. Patrimostat 2025. culture.gouv.fr.
• Musée de Normandie, Ville de Caen. “Le château de Caen.” musee-de-normandie.caen.fr.
• Musée de Normandie, Ville de Caen. “Accès, horaires, tarifs.” musee-de-normandie.caen.fr.
• Musée de Normandie, Ville de Caen. Caen Castle Teacher’s File. musee-de-normandie.caen.fr.
• Musée de Normandie, Ville de Caen. “La salle de l’Échiquier.” musee-de-normandie.caen.fr.
• Musée de Normandie, Ville de Caen. “Le donjon.” musee-de-normandie.caen.fr.
• Musée de Normandie, Ville de Caen. “Le rempart sur la ville et la tour Puchot.” musee-de-normandie.caen.fr.
• Normandie Tourisme. “Châteaux et manoirs en Normandie.” normandie-tourisme.fr.
• Office de Tourisme Nouvelle Normandie and Ville des Andelys. Dépliant Château-Gaillard (2023). ville-andelys.fr.
• openrouteservice, Heidelberg Institute for Geoinformation Technology. Matrix API, driving-car profile, queried 1 September 2026. openrouteservice.org.
• Powicke, F. M. The Loss of Normandy (1189-1204): Studies in the History of the Angevin Empire. Manchester University Press, 1913. archive.org.
• SNCF Open Data. “Liste des gares.” ressources.data.sncf.com.
• Spear, David. “Deux visions d’Henri Ier Beauclerc.” Études Normandes 55-4 (2006): 81-82. persee.fr.
• Ville de Gisors. “Château.” ville-gisors.fr.
• Ville de Gisors. “Préparer votre visite.” ville-gisors.fr.
• Ville des Andelys. “Château-Gaillard.” ville-andelys.fr.
• Westminster Abbey. “William I (the Conqueror).” westminster-abbey.org.
• Westminster Abbey. “William II.” westminster-abbey.org.
• Westminster Abbey. “Henry I.” westminster-abbey.org.
• Westminster Abbey. “Richard I.” westminster-abbey.org.

Image credits. Hero, Chateau Gaillard above the Seine: Photo: charles / Adobe Stock. Source: Adobe Stock 310708824; Falaise from the town lane: Photo: david-bgn / Adobe Stock; Locator map: Map by StoneKeep Atlas; region outlines, coastline and rivers from Natural Earth (public domain); Mont-Saint-Michel from the air at sunset: Photo: Giladtop, CC BY-SA 4.0; Falaise on its outcrop: Photo: John / Adobe Stock; The curtain wall at Caen: Photo: Richard Semik / Adobe Stock; The donjon at Chateau Gaillard: Photo: Zairon, CC BY-SA 4.0; The keep on its motte at Gisors: Photo: JONATHAN / Adobe Stock. Freely licensed images are resized to fit; otherwise unaltered.