Under which French king was the Louvre originally built as a fortress?

The Louvre was originally built as a fortress under Philip II of France.

Around 1190, Philip II—also known as Philip Augustus—ordered a defensive fortress to be constructed on Paris’s right bank beside the Seine. It stood near the western edge of the medieval city and helped protect Paris from threats approaching along the river or from Normandy, then controlled by England. The fortress was completed around 1202.

The original structure was very different from the immense palace and museum seen today. It was roughly square, surrounded by a water-filled moat, and reinforced with thick curtain walls and defensive towers. Archaeological remains of its foundations can still be seen beneath the Louvre’s Cour Carrée.

Later rulers transformed the fortress into a royal residence. Charles V expanded it in the 14th century, and Francis I began major Renaissance rebuilding in the 16th century. Napoleon and Louis XIV were important later figures in the Louvre’s history, but neither built the original fortress.