How did Saint Philip die?

Although the place, date, and cause of Saint Philip’s death are uncertain, one tradition holds that he was martyred and died a torturous death. In a Catechesis at a General Audience that Pope Benedict XVI gave on Philip the Apostle, he commented,

According to certain later accounts (Acts of Philip and others), our Apostle is said to have evangelized first Greece and then Frisia, where he is supposed to have died, in Hierapolis, by a torture described variously as crucifixion or stoning.

It is important to mention that 2nd century books, such as the Acts of Philip, while attributed to the Apostle are not recognized by the Church as genuinely his, nor inspired by God.