Context : William II, Count of Hainaut (1307 -- 26 September 1345) was William IV of Avesnes, William IV of Holland and William III of Zeeland from 1337 to his death, succeeding his father, William I. He married Joanna, Duchess of Brabant and Limburg in 1334, but had no issue. 
Answer : Joanna, Duchess of Brabant
What is William II, Count of Hainaut's spouse's name?