Philip III became King of France following the death of his father Louis IX during the Eighth Crusade.

Philip III, called the Bold, was King of France from 1270 until his death in 1285. His father, Louis IX, died in Tunis during the Eighth Crusade. Philip, who was accompanying him, returned to France and was anointed king at Reims in 1271.

Louis IX, also known as Saint Louis, was King of France from 1226 until his death in 1270. He is widely recognized as the most distinguished of the Direct Capetians. Following the death of his father, Louis VIII, he was crowned in Reims at the age of 12. His mother, Blanche of Castile, effectively ruled the kingdom as regent until he came of age, and continued to serve as his trusted adviser until her death. During his formative years, Blanche successfully confronted rebellious vassals and championed the Capetian cause in the Albigensian Crusade, which had been ongoing for the past two decades.

The Eighth Crusade was the second Crusade launched by Louis IX of France, this one against the Hafsid dynasty in Tunisia in 1270. It is also known as the Crusade of Louis IX Against Tunis or the Second Crusade of Louis. The Crusade did not see any significant fighting as Louis died of dysentery shortly after arriving on the shores of Tunisia. The Treaty of Tunis was negotiated between the Crusaders and the Hafsids. No changes in territory occurred, though there were commercial and some political rights granted to the Christians. The Crusaders withdrew back to Europe soon after.