Complex sentence: In 1402 Antoine entered the court of the third Angevin dynasty at Anjou, probably as a page, and in 1407 he was at Messina with Louis II, Duke of Bourbon, who had gone there to enforce his claim to the kingdom of Sicily.
Split into simpler sentences: In 1402 Antoine entered the court of the third Angevin dynasty at Anjou, probably as a page. In 1407 he was at Messina with Louis II, Duke of Bourbon, who had gone there to enforce his claim to the kingdom of Sicily.