Margaret of Hungary, born 1175, died 1223, was the daughter of king Bela III of Hungary. In 1185 she married the Byzantine Emperor Isaac II Angelus, and in 1204 Boniface of Montferrat, who was soon to become king of Thessalonica. To Boniface she bore a son Demetrius in 1207. In the same year, on his father's death, Demetrius became king of Thessalonica. Events Ruaidri Ua Conchobair (Rory OConner), last High King of Ireland, submits to Henry II as vassal of Ireland with the Treaty of Windsor Ly Cao Ton becomes ruler of Vietnam William of Tyre becomes archbishop of Tyre Massacre of Abergavenny ends with several noblemen dead at the hands... // Events August 6 - Louis VIII is crowned King of France. ... Bela III of Hungary (Hungarian , Slovak: Belo III), born in 1148, was King of Hungary circa 1172_1196. ... Events April 25 - Genpei War - Naval battle of Dan-no-ura leads to Minamoto victory in Japan Templars settle in London and begin the building of New Temple Church End of the Heian Period and beginning of the Kamakura period in Japan. ... Isaac II Angelus (or Isaakios Angelos) (September 1156-1204), was the Byzantine emperor from 1185-1195, and again 1203-1204. ... Boniface of Montferrat (c. ... The Kingdom of Thessalonica was a short-lived Crusader State founded after the Fourth Crusade. ...