Bouchard IV of Avesnes

by marriage.

Bouchard began his career as a cantor and subdeacon in the church of Laon. In 1212, he was named bailiff of Hainaut. In this capacity, he served as tutor and guardian of the young Margaret, sister of Joanna, Countess of Flanders and Hainault. Soon he married Margaret, though she was only ten years old and the marriage could not be consummated. Neither did Joanna or Count Ferdinand give their consent.

Bouchard lived a war-like life. He invaded the territory of his brother Walter, who had received most of their patrimony. He then invaded Flanders and forced Joanna and Ferdinand to recognise his marriage to Margaret. He then fought at the Battle of Bouvines in 1214, under the (losing) Flemish banner. Philip Augustus, the king of France and victor of Bouvines, then councilled the pope, Innocent III, to declared the marriage of Bouchard and Margaret illegal. Innocent eventually excommunicated the couple on 19 January 1216. They took refuge in Luxembourg. Bouchard was captured in combat and imprisoned in Ghent for two years. To obtain his liberation, Margaret accepted the dissolution of the marriage and Bouchard left for Italy to fight for the Holy See. Upon his return, he was decapitated at Rupelmonde on the orders of Joanna.

Bouchard and Margaret had three children, who played an important part in the War of the Succession of Flanders and Hainault:

* Baldwin (d.c.1219), took refuge with his parents in Luxembourg
* John I (c.1218 – 1257), later Count of Hainault
* Baldwin (c.1219 – 1295), Lord of Beaumont