William I, Count of Hainaut, Count of Hainaut, Count of Holland, Count of Zeeland, was born 1286 to John II, Count of Hainaut (1247-1304) and Philippa of Luxembourg (1252-1311) and died 7 June 1337 of unspecified causes. He married Jeanne de Valois (c1294-1342) 19 May 1305 JL . William I of England (1027-1087), Alfred the Great (849-899)/s, Charlemagne (747-814)/s, Hugh Capet (c940-996)/s, William I of England (1027-1087)/s, Rollo of Normandy (860-932)/s.
|Offspring of William d'Avesnes and Jeanne de Valois (c1294-1342)|
|Joanna of Hainaut (c1307-1374)||1374||Wilhelm I. von Jülich (c1299-1361)|
|Margaret II of Hainaut (1311-1356)||1311||23 June 1356||Ludwig IV. von Wittelsbach (1282-1347)|
|Philippa of Hainaut (1311-1369)||24 June 1311 Valenciennes, Nord, France||1369 Windsor Castle, Windsor, Berkshire, England, United Kingdom||Edward III of England (1312-1377)|
|William II of Hainaut (1307-1345)||1307||26 September 1345||Johanna van Brabant (1322-1406)|
|Isabella of Hainaut (1323-1361)|
|Louis of Hainaut (1325-1328)|