Marie of Artois

Marie of Artois (1291–1365), daughter of Philip of Artois and sister of Robert III, married John I of Namur in 1310. He gave her Wijnendale Castle and lands in Flanders. While he was in Italy with Emperor Henry VII, a 1313 revolt at Namur shut her and her three children in Namur Castle until John had the Count of Looz put it down.

Widowed in 1330, she saw three sons succeed as margrave and die within seven years. Her relations with the first, John II, had already soured after she intervened at Sluis.

In 1337 her youngest son William inherited at fifteen, and she ruled Namur as regent until 1340. In 1342 she bought Poilvache from John the Blind of Luxembourg, giving it to William in 1353.