Gregory X was a pope who served from 1271 to 1276. He was born as Hugh of Montaigu in 1210 and became a cardinal before his papacy. His election as pope came after a lengthy vacancy of nearly three years, which was marked by political struggles within the Church. During his papacy, Gregory X focused on reforming the Church and promoting peace in Europe. He is known for convening the Second Council of Lyon in 1274, which aimed to address issues such as the relationship between the Roman Catholic Church and the Eastern Orthodox Church. His efforts laid the groundwork for future ecumenical dialogues.