Alice of Hainault had several brothers, one of whom, William III, Count of Hainault, was the father of Edward III's wife, Philippa of Hainault. Another brother was John, Lord of Beaumont, known in England as Sir John of Hainault. In 1326 he was influential in the invasion of England by Isabella of France and Roger Mortimer, 1st Earl of March, for which he was paid £32,722 or more. A third brother, also named John, who had been contracted in marriage to Blanche of France, the daughter of Philip III of France, was slain in 1302 at the Battle of Courtrai.