Philip Augustus became co-regent with his father in 1179 and King of France in 1180. For the next six years Philip fought a coalition of barons in Flanders, Burgundy, and champagne and, at their expense, increased the Royal domain. Philip allied himself with Richard, Duke of Normandy and embarked on the Third Crusade. The kings quarreled, however, and Philip returned to France in 1191.

Allied with the Holy Roman Emperor Henry VI and King Richard’s brother, John, King Philip attacked Richard’s territories in France. Richard returned in 1194 and went to war against Philip. By the time of Richard’s death in 1199, Philip had been forced to surrender most of the territory he had annexed. Philip subsequently warred against King John of England in 1199, and between 1202 and 1205, he more than doubled his territory by annexing Normandy, Maine, Brittany, Anjou, Touraine, and Poitou.

A coalition of European powers, including England, challenged the growing power of France in 1214. Philip’s forces, however, decisively defeated the coalition at the Battle of Bouvines, establishing France as a leading country in Europe.

Philip increased the Royal power not only by extending the Royal domain but also by reducing the power of the feudal lords. He replaced the noble officers at court with an advisory council appointed from the middle class and supported the communes against the nobles. France prospered from his judicial, financial, and administrative reorganization of the government. Serfdom declined, towns grew, and commerce flourished. Philip established Paris as the fixed capital of France, paved the streets, and had many new buildings constructed in the city. King Philip II, one of the most powerful European monarchs of the Middle Ages, died in 1223.