John Angelos of Syrmia

[5][6] In 1225, Ugrin Csák, the Archbishop of Kalocsa, tried to organize the Bosnian Crusade, and attempted to commission local feudal lords for that endeavor.

[7] During the 1230s and early 1240s, John continued to play a prominent role both in southern regions of the Kingdom of Hungary and in the Hungarian royal court.

He died by 1250, since in the July of that year his wife Matilda was already mentioned as "noble lady, widow of lord John, countess of Požega" (lat.

nobilis domine relicte domini Johannis, comitisse de Posoga),[8][9][10][6] and later documents related to marriage of their daughter Maria also mention him as deceased.

[15][16] Those data allowed Gordon McDaniel to resolve genealogical questions related to Maria's parents,[17][18] while the identity of John's son-in-law and Maria's husband Anselm of Cayeux was a subject of several additional genealogical and historical studies, that tried to resolve complex questions related to attribution of sources on at least two persons (father and son) who had the same name: Anseau de Cayeux.

[19] In the summer of 1280, king Charles I of Sicily allowed John's daughter Maria to travel from Apulia to Serbia, to visit her sister, the queen of Serbia (Latin: Quia nobilis mulier domina Maria de Chaurs cum filio suo et familia eiusdem domine intendit transfretare ad presens ad partes Servie visura dominam reginam Servie sororem suam).