Gwynedd. Roger Bacon, Franciscan friar and University of Oxford lecturer, is arrested for spreading anti-Church views; specifically, the Church's stance on Greek philosopher Galen. Levant April 15 – Battle of Elbistan: A Mamluk army (some 14,000 men) under Sultan Baibars marches from Syria into the Mongol-dominated Sultanate of Rum and attacks the Mongol occupation force at Elbistan. Baibars, with at least 10,000 horsemen, defeats and overwhelms the Mongol forces. After the battle, he marches unopposed to Kayseri in the heart of Anatolia in triumph and enters the city on April 23. Asia Battle of Ngasaunggyan: A Burmese army (some 80,000 men) led by King Narathihapate (or Sithu IV) invades Mongol territory in Yunnan. The invasion is repelled by the Mongol forces, who counterattack, reaching as far south as the fortress city of Kaungsin ("Gold Teeth"), which guards the Bhamo Pass in northern Myanmar. Later, the Burmese Pagan Empire begins to disintegrate after several Mongol invasions under Kublai Khan. Migration of the (Southern) Song Dynasty: Some 50,000 citizens of the Song Dynasty in China become the first recorded inhabitants of Macau, as they seek refuge from the invading armies of the Yuan Dynasty. They also stay for a short period in Kowloon (or New Kowloon). In Japan, a 20 kilometer stone wall defending the coast of Hakata Bay at Fukuoka on the island of Kyushu is completed; it is built in response to the attempted invasion by the Mongol Yuan Dynasty (see 1274). By topic Religion March 7 – Condemnation of 1277: Pope John XXI instructs Étienne Tempier, bishop of Paris, to investigate the complaints of theologians in France. By order 219 propositions of philosophical and theological doctrines such as Averroism are prohibited from discussion in the University of Paris, under a decree promulgated by Tempier. April – John XXI sends a papal embassy to Constantinople to force Michael VIII (Palaiologos), his 18-year-old son and heir Andronikos, and Patriarch John XI Bekkos, to reaffirm their allegiance to the Union of Lyon in the Palace of Blachernae. Michael refuses to accept a religious union of the Greek Orthodox Church with Rome. May 20 – John XXI dies after an 8-month pontificate at Viterbo. He is succeeded by Nicholas III as the 188th pope of the Catholic Church (until 1280). Births January 7 – Kanzan Egen, Japanese monk (d. 1360) January 21 – Galeazzo I, Italian nobleman (d. 1328) March 26 – Christina