MARGIT (1175-after 3 Mar 1229). The Chronicle of Alberic de Trois-Fontaines names (in order) "Haymericum et Andream…et duas reginas Constantiam de Boemia et Margaretam de Grecia" as children of "rex Bela de Hungaria" & his wife Agnes[793]. Niketas Choniates records the marriage of Emperor Isaakios and "Belæ Hungariæ regis filiam", commenting that she was only ten years old at the time[794]. She brought Beograd, Branicevo and probably Niš as part of her dowry for her first marriage[795]. The special wedding tax levied by Emperor Isaakios II to finance their elaborate nuptial ceremonies may have contributed to attracting support for the rebellion in Bulgaria by the brothers Ivan Asen and Tedor[796]. She adopted the name MARIA in Byzantium. The Cronica Fratris Salimbene de Adam records the marriage of "Bonifacius marchio" and "Margaritam imperatricem condam Ysachii, sororem Aimerici regis Ungari"[797]. Villehardouin records that the wife of Emperor Isaakios, and stepmother of his son, was "the king of Hungary's sister", in a later passage naming her "the Empress Marie"[798]. Georgius Akropolites records that "rex Thessalonicæ" married "Mariam Ungaram", widow of "imperatori Isaacio"[799]. Villehardouin records the marriage of "the Marquis Boniface de Montferrat" and "the lady who had been the Emperor Isaac's wife…the king of Hungary's sister"[800]. Her second marriage was arranged by Bonifazio to advance his claim to be installed as emperor of the new Latin Empire of Constantinople[801], but he was outmanoeuvred by Enrico Dandolo Doge of Venice who secured the appointment of Baudouin Count of Flanders who was considered a less powerful candidate. Her second husband installed her as regent of Thessaloniki while he was on campaign to conquer Thessaly[802]. She was also regent for her infant son after the death of her husband, but in the face of opposition from local nobles was replaced by Uberto di Biandrate. The primary source which confirms her third marriage has not yet been identified. She was restored as regent by Henri Latin Emperor of Constantinople to whom Uberto refused to swear allegiance, after the latter was captured in Euboea by the emperor in 1209[803]. Pope Gregory IX confirmed that "[Margaretha] soror…regis Ungarie" acquired "terram…ulterior Sirmia" by bull dated 3 Mar 1229[804]. m firstly (1185) as his second wife, Emperor ISAAKIOS II, son of ANDRONIKOS Dukas Angelos & his wife Euphrosyne Kastamonitissa ([1155]-Constantinople in prison [28 Jan/12 Apr] 1204). m secondly (1204) as his third wife, BONIFAZIO I Marchese di Monferrato King of Thessaloniki, son of GUGLIELMO V "il Vecchio" Marchese di Monferrato & his wife Judith of Austria [Babenberg] (1150-killed in battle 4 Sep 1207). King of Thessaloniki 1204. m thirdly (after Sep 1207) NICOLAS de Saint-Omer Lord of Thebes, son of GUILLAUME IV Châtelain de Saint-Omer, Seigneur de Fauquembergues & his first wife Ida d'Avesnes (-[1217/19]).
http://fmg.ac/Projects/MedLands/HUNGARY.htm#_Toc146273221