The Château de Fontainebleau has developed around the keep, showing the building’s mediaeval origins. These probably date from before its use as a royal residence, but it is the King’s Chamber, long situated on the first floor (now known as the Salles Saint-Louis), which is the real seat of power.
The first recorded reference to the Château de Fontainebleau in a royal charter dates back to 1137, the year of the accession of Louis VII, known as Louis the Younger. The huge keep (or central tower) dates from this period. In 1169, Archbishop of Canterbury Thomas à Becket, then exiled in France, consecrated the Château de Fontainebleau chapel to both the Virgin Mary and Saint Saturnin. In 1259 Saint Louis, who was very fond of his fortified castle in Fontainebleau, established a monastery hospital there, presided over by the Trinitarian or Mathurin monks. The foundations of their chapel and other monastery buildings are all that remain from this original configuration, now located near to the current Chapel of the Trinity. Philip IV of France (1268-1314 ; known as Philip the Fair, the son of Philip III of France and Isabella of Aragon) was born and died at Fontainebleau. In 1323 his daughter Isabella of France, queen consort of Edward II of England, came to visit him in Fontainebleau. It was at Fontainebleau in 1332 that the marriage contract between Jean de France (the future Jean II, or John the Good) and Bonne of Bohemia was signed. Charles VII (King of France from 1422 to 1461) began extending the château complex from the start of his reign. He made several extended visits there, sometimes staying for over six months at a time.
Saint Louis founded a monastery hospital at the edges of what is now the Main Courtyard (also known as the Cour du Cheval Blanc ) or the Cour des Adieux. Part of the main building which looks out onto this courtyard, the current Chapel of the Trinity (rebuilt in the 16th century) is on the site of the Trinitarian or Mathurin monks’ chapel. The monastery buildings were built alongside the Cour d’Honneur and the courtyard which looks out over the town still bears the name of the Cour des Mathurins, after the Mathurin monks. The monastery was to be acquired by Francis I during the extension works which he commissioned in 1528.