The Louvre was renovated frequently through the Middle Ages. Under Louis IX in the mid-13th century, the Louvre became the home of the royal treasury. The castle soon gained a dual function: in addition to its protective role, it became one of the residences of the king and the court, along with the Château de Vincennes, the Hotel Saint-Pol in Le Marais and the Conciergerie of the Île de la Cité.
The fortress was enlarged and beautified in the 14th century by Charles V, making it the most celebrated royal residence in Europe of its time. Charles V began the enlargement of the Louvre in 1358, but his work was ruined in the course of the Hundred Years War and demolished in the 16th century by King Francis I, to make room for a new structure built in the Renaissance style