On 18 November 1282, Pope Martin IV opened proceedings against King Pedro of Aragon, because he had invaded the territory of Sicily, which was a papal fief, and was usurping the throne of Sicily, calling himself King.
November 1282, Pope Martin IV opened proceedings against King Pedro of Aragon. This was on 18. He had invaded the territory of Sicily. He was usurping the throne of Sicily. He was calling himself King. Sicily was a papal fief.