From the website of The Association of Friends of the Château d'Eu...a marvelous site every royal watcher ought to visit!
Situated on the very edge of Normandy, the  construction of the present Château of Eu was begun in 1578 by Henri of  Guise and Catherine of Cleves, before being completed in 1665 by the  Grande Mademoiselle, King Louis XIV’s first cousin. In the 18th Century  it was in turn the property of the Duke of Maine and the Duke of  Penthièvre before becoming the Summer Palace of King Louis-Philippe in  the 19th century. Following the creation of the Entente Cordiale between  France and Great Britain, the French sovereign invited Queen Victoria  of England to Eu on official visits in 1843 and 1845.
 As the residence of the Princes of Orleans until  the beginning of the 20th century, the Château underwent a period of  extensive renovation during the Third French Republic between 1872 and  1886. These building works were supervised by the famous architect  Eugène Viollet-Le-Duc. 
Although partly destroyed by fore in 1902, the  Château was purchased and restored from 1905 onwards by the Brazilian  Imperial Family - the Orleans-Braganzas. It was at Eu that lived the  eldest daughter of Emperor Pedro II of Brazil, Isabel of Braganza, and  her husband, Prince Gaston of Orleans, Count of Eu as well as King  Louis-Philippe’s grandson.

In  1954 the Château of Eu was acquired by the Dom Pedro II Historical  Study Society which in turn sold it in 1962 to the local government  authority – the Département of Seine-Maritime.
In 1964 the town of Eu purchased the château which after 1973 would house the mayor’s office and the Louis-Philippe Museum.
The Museum nowadays
 The rooms of the Louis-Philippe Museum are mainly  devoted to the King and his family. The setting is most appropriate as  the site and collections recall the golden age of the Château when it  was the Summer Palace and favourite residence of the last King of  France. Visitors can also admire the major building works carried out by  Eugène Viollet-Le-Duc at the end of the 19th century. Part of the  collections of the Brazilian Family are also on show including  anthropology, portraits, the Imperial Library of 22,000 volumes as well  as the royal carriage which once belonged to King John V of Portugal.  This vehicle dates from 1727, which makes it the oldest French-made  carriage on exhibition in France.
 The Galerie des Guise may be considered the most  splendid room in the Château. Thanks to the purchase in 2000 of 145  historical paintings which originally formed part of the collections of  the Grande Mademoiselle and of Louis-Philippe at Eu, this gallery is in  the process of being restored to its original state and we are looking  forward to its completion. This is already the case for the panelled  ceiling which had been badly damaged by the fire in 1902. The Galerie  des Guise is a key element for both the architecture of and the history  of the Château and it would provide Louis-Philippe with a direct model  for the Museum of French History which he established at Versailles. 
 A part of the former royal domain has remained in  private hands and still belongs to the Orleans Family whose members  regularly stay at Eu. This is the case for Prince Jacques of Orleans,  Duke of Orleans and  Prince Michel of Orleans, Count of Evreux : both  sons and heirs of Princess Isabelle of Orleans-Braganza, 
Countess of Paris  (1911-2003), who was grand-daughter of Prince Gaston of Orleans, Count  of Eu and also Founder-President of the Association of the Friends of  the Louis-Philippe Museum at the Château of Eu.