John Angelus or Angelos (Greek: Ἰωάννης Ἄγγελος, Hungarian: Angelos János; c. 1193 – 1259), also known as Good John (Καλοϊωάννης, Kaloiōannēs in Greek), was a Byzantine prince who migrated to Hungary and ruled the Duchy of Syrmia (Sirmium, Szerém) and its surroundings from 1235 until 1254, as a vassal under king Béla IV of Hungary, his maternal relative.
John Angelus was the son of Isaac II Angelos, the Byzantine Emperor from 1185 to 1195, and again from 1203 to 1204; and Margaret of Hungary, the daughter of King Béla III (r. 1172–1196) and sister of King Emeric (r. 1196–1204). John had three older siblings from his father's first marriage: Euphrosyne Angelina, Irene Angelina and Alexios IV Angelos, while he had a younger full brother, Manuel Angelos (b. after 1195 – d. 1212).
The family found refuge in the Hungarian court in 1222.
Andrew II of Hungary (r. 1205–1235), his uncle, gave him "Syrmia and beyond", i.e. south of the Sava river, including Belgrade, and the districts of Barancs and Macsó, which he ruled until 1254.
Béla IV appointed John Angelus as the governor of Syrmia, and Rostislav Mikhailovich as the governor of Slavonia, securing his southern boundaries while heading towards the Adriatic. Another source claims that he ruled Syrmia and Bačka from ca. 1230.
In 1221, Pope Honorius III demanded that the "heretics" (Bogomils) be exterminated in Bosnia. His chaplain Aconcio was unable to gain any followers in Ragusa, and died while in Bosnia. Ugrin Csák, the Archbishop of Kalocsa, proposed to Andrew II of Hungary that he would lead the Bosnian Crusade, and the king and pope promised him all lands that he would clear of heretics. Ugrin overrated himself, and instead gave 200 silver marks to John Angelus, the ruler of Syrmia, to perform the task. John took the money but never acted against the Bogomils, despite being reminded of his obigation by Pope Honorius III in 1227.
John married Mathilde (ca. 1216–), the daughter of Marguerite de Courtenay (the sister of the Latin emperors Robert and Baldwin II) and Henry I, Count of Vianden. They had at least one daughter, Maria Angelina, who married Anseau de Cayeux. In 1280, Charles I of Sicily issued documents to Maria Angelina, allowing her to travel from Apulia to Serbia to visit "her sister the queen of Serbia", Helen of Anjou.
|Ancestors of John Angelus of Syrmia|