Guy de Luxembourg, who was born in 1340 and died in 1371, was comte de Saint-Pol from 1360 to 1371 and comte de Ligny, Lord of Roussy de Beauvoir and 1364 to 1371. He was the son of John I, lord of Ligny, and Alix de Dampierre-Flanders, Lady Richebourg.
He married in 1354 Mahaut de Chatillon (1335 † 1378), Countess de Saint-Pol, daughter of Jean de Chatillon, Comte de Saint-Pol and Jeanne de Fiennes, and had:
* Waleran III (1356 † 1415), Count of Ligny and Saint-Pol.
* Pierre (1369 † 1387), bishop of Metz and cardinal
* Jean (1370 † 1397), Lord de Beauvoir and marriage Count de Brienne and Conversano. He is the author of the younger branch of Saint-Pol and the father of Pierre de Luxembourg, Comte de Saint-Pol, and Jean de Luxembourg, Comte de Ligny
* André (1396), bishop of Cambrai
* Mary, married to Jean de Conde († 1391), and then to Simon, Comte de Salm († 1397)
* Jeanne († 1430), Countess of Ligny and Saint-Pol.
Guy de Luxembourg 
- b.~ 1180 d.02 Jul 1226
- b.1186 d.12 Feb 1247