Philip III of France

Philip III of France
April 3, 1245 – October 5, 1285

On April 3, 1245, Philip III of France was born to King Louis IX and Queen Margaret in Poissy, France. As the king’s second son, Philip wasn’t intended to inherit the French throne. However, upon his older brother Louis’s death in 1260, the prince became the new heir. During his reign, King Louis had gained a reputation as a respected ruler and devoted Christian. When the Eighth Crusade was announced, the king readily joined in reclaiming Jerusalem from the Muslims.

In July 1270, Louis IX and Philip landed in north Africa with the French army. While fighting in Tunis, the prince proved himself a skilled and aggressive warrior, earning the title of “the bold.” Eventually, dysentery swept through the army’s ranks. In time, Louis became infected. The disease proved fatal and caused the king’s death on August 25, 1270. After his demise, Philip returned to France with his father’s body. The following year, the prince succeeded to the throne as King Philip III.

King of France

Philip III’s accession began on a sad note. Shortly after his father’s death, the king’s wife, Isabella, died after falling from her horse. Devastated by these losses, Philip retreated into governing. During his reign, the king retained many of Louis IX’s advisors. By doing this, the king hoped to continue his father’s successful administration. In 1276, Philip experienced another loss after his heir, Prince Louis, died.

Expansion of the Kingdom

┬áIn 1271, Philip’s uncle, Alphonse, died without an heir. As a result, Alphonse’s vast holdings returned to the throne, which enlarged the monarchy. In 1274, Henry III of Navarre died and left behind vast estates to his daughter, Joan. In 1284, the king’s son, Prince Philip, married Joan, an heiress to Navarre, Champagne, and Brie. Through their marriage, Joan brought these holdings under Capetian control. Philip would continue expanding his kingdom by gaining other smaller territories throughout his reign.

Military Campaigns

As the king experienced success within France, Philip III sought to expand French power abroad. While Louis IX had avoided involving himself in foreign conflicts, Philip believed that he could be successful. In 1276, the king declared war on Castile. Philip did so to support his nephew’s claims as heirs. However, he would abandon the campaign before they could claim the throne. Despite this setback, Philip remained determined.

In 1284, Pope Martin IV called upon Philip III to invade Aragon. King Peter III had angered Martin by conquering Sicily. A staunch Christian, Philip obeyed and declared war on Peter. Thus, the Aragonese Crusade had begun.

In May 1285, the French army invaded Aragon. As his soldiers traveled, the king’s men began to commit various atrocities. In response, angered Aragonese started harassing the French by using guerilla tactics. Although he would win a victory at Gerona, Philip would retreat after his fleet was destroyed at Las Formiguas.

Final Year

Philip IV of France
Prince Philip (the future Philip IV of France)

After his second failed military campaign, Philip III and his remaining men traveled back to France. As he traveled, the king began to suffer from a fever. Unable to recover, Philip would succumb to it on October 5, 1285. Upon his death, Prince Philip succeeded his father as King Philip IV.


Philip III of France’s reign followed one of the most successful in France’s history: Louis IX. Despite being overshadowed by his father, Philip succeeded in his own right. Over fifteen years, the king expanded the monarchy’s territory and increased Capetian power. These advancements would prove invaluable to his descendants. Although he failed militarily, the king left behind a secure and powerful France to Philip IV.


Bradbury, J. (2010). The Capetians: Kings of France, 987-1328. London: Hambledon Continuum.

Dougherty, M. J. (2018). Crusaders, Persecutors and Religious Reformers. In Kings & Queens of the Medieval World: From Conquerors and Exiles to Madmen and Saints (pp. 76-78). London: Amber Books.

Philip III. (n.d.). Retrieved January 19, 2021, from


Andy Tree

I'm a European history enthusiast who seeks to share his passion with others. I hope to inform and inspire readers with my posts!

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