John I, Count of Hainaut
John of Avesnes ( born May 1, 1218 Houffalize, † December 24, 1257 ) from the House of Avesnes was 1246-1257 Count of Hainaut.
He was the eldest son of Margaret II of Flanders from her first marriage with Burkhard of Avesnes, his brother was the chronicler Baldwin of Avesnes. The marriage ended in divorce due to pressure from Margaret's older sister, the Countess Joan of Flanders to 1221. His mother then married William II of Dampierre, with whom she had two sons, William and Guido.
The legal status of the second marriage caused a great stir, as key successions depended on the legitimacy of children. Margaret inherited upon the death of her sister Johanna in December 1244 the counties of Hainault and Flanders. As Margaret now her son Wilhelm designated as sole heir Johann rebelled against it. In the Flemish War of Succession, Johann successfully fought against his mother and his half-brothers in 1246 the rights to the County of Hainaut, he could actually push through to 1254.
In John's death in 1257 was his eldest son, John II, a minor, which is why John's mother Margaret has established itself as the Countess again. Only after her death in 1280 was this the County of Hainaut.
Marriage and issue
He married 1246 Adelaide of Holland († 1284), daughter of Count Florens IV of Holland ( Gerulfinger ). Adelheit brother William II of Holland supported Johann's struggle for Hainaut prevail. 1258-1284 Adelheid was regent of the County of Holland.
With Adelheid he had the following children:
- John II (* 1248, † 1304) from 1280 Count of Hainaut, Count of Holland from 1299
- Johanna († 1304) Abbess of Flines
- Burchard (* 1251, † 1296 ) from 1282 Bishop of Metz
- Guido (* 1253, † 1317 ) from 1301 Bishop of Utrecht
- Wilhelm ( * 1254, † 1296 ) from 1292 Bishop of Cambrai
- Florence ( * 1255, † 1297 ) Governor of Zeeland, Prince of Achaia