Philip Augustus becomes king of France at the age of fifteen.

Philip II, also known as Philip Augustus, was King of France from 1180 to 1223. His predecessors had been known as kings of the Franks, but from 1190 onward, Philip became the first French monarch to style himself "King of France". The son of King Louis VII and his third wife, Adela of Champagne, he was originally nicknamed 'God-given' because he was a first son and born late in his father's life. Philip was given the epithet "Augustus" by the chronicler Rigord for having extended the crown lands of France so remarkably.

September 18 is the 261st day of the year in the Gregorian calendar; 104 days remain until the end of the year.