Vem gifte sig med Adelaide of Holland?

Adelaide of Holland (Dutch: Aleide (Aleidis); c. 1230 – buried 9 April 1284) was a Countess of Hainaut by marriage to John I, Count of Hainaut. She acted as the regent of the County of Holland during the minority of her nephew Count Floris V between 1256 and 1263.

She was a daughter of Floris IV, Count of Holland and Matilda of Brabant, and a sister of William II, Count of Holland and King of Germany.

John of Avesnes (1 May 1218 – 24 December 1257) was the count of Hainaut from 1246 to his death.