Jean Duke of Luxembourg, who was born in 1300 and died in 1364, was lord of Ligny, Roussy de Beauvoir and 1354 to 1364. He was the son of Waleran II, Comte de Ligny and Guyotte of Lille.
He married in 1330 Alix de Dampierre-Flanders (1322 † 1346), Richebourg lady, the daughter of Guy de Dampierre, Lord of Richebourg and Beatrice of Putten in Strijen, and had:
* Guy (1340 † 1371) Count of Ligny, Lord of Roussy and de Beauvoir
* Jean (1360), Lord of Roussy
* Jean (1342 † 1373), Archbishop of Mainz (1371-1373)
* Henri (1344 † 1366) in Cologne and Canon Cambrai
* Waleran, cited in 1347
* Jacques
* Jeanne (1392), Countess of Faucquenberghe married to:
1. Guy de Chatillon († 1360), Comte de Saint-Pol
2. Guy VIII (1427), Baron de La Rochefoucauld
* Marie († 1376/1382), married to Henry V of Vaudémont (1327 † 1365), sire of Joinville, Count of Vaudémont
Philippote * (1359), married to Ralph, sire of Reineval
* Catherine († 1366), married to Daniel de Halewyn († 1365)
Widowed, he remarried to Joan Bacon.