Margaret of Hungary

Two other siblings, Solomon and Stephen, are mentioned in the standard reference work on the genealogy of medieval European aristocracy, "Europäische Stammtafeln" (1978–1995) by Detlev Schwennicke.

[2] In January 1186, 10 year old Margaret married the Byzantine Emperor Isaac II Angelos, who wanted a politically strategic alliance with Hungary in order to strengthen his claim to the throne and due to the changing policy towards dynastic marriages with foreign rulers.

Her step-son Alexios IV Angelos had escaped and went to join the military discussions which were shortly to launch the Fourth Crusade.

There, he and others convinced the Crusaders to besiege Constantinople in order to depose his uncle and restore his imprisoned father and himself to the throne.

Margaret's husband Isaac died in February 1204, "whose end was accelerated by the fate of his son", who was "strangled in his dungeon after poison had failed to do its work".

[5] When Boniface of Montferrat, commander of the land forces at the taken of Constantinople, took the Boukoleon Palace, it was found that Margaret had taken refuge there alongside another dowager empress, the French Agnes of France.

Later that year, in Constantinople the widowed Margaret, dowager Empress, married Boniface of Montferrat, with the wedding taking place according to the rites of the Latin church.

[6][7] The marriage was intended to both bolster Boniface's position with the Byzantine aristocracy and provide him with Margaret's Hungarian connection.

When the Emperor Henry of Flanders visited Thessalonica to receive the homage in the infant's name, he was barred from the city by the bailiff Biandrate until he would agree to outrageous demands.

[11] Nicholas was the son of Geoffrey of Saint Omer, had accompanied his uncle on the fourth crusade and was granted a fief in Doris.