In 1357, at the age of seven, she married Philip of Rouvres, grandson and heir of Eudes IV, Duke of Burgundy. Philip was eleven years old and her second cousin. He was count of Burgundy and Artois (1347-1361), duke of Burgundy (1349-1361), count of Auvergne and Boulogne (1360-1361).
Margaret was widowed in 1361 and in 1363 Philip the Bold became duke of Burgundy and married Margaret in 1369. Philip had earlier been Duke of Touraine (1359-1363), and was later also count of Charolais (1390-1404). When Margaret's father died in 1383, she and Philip inherited the counties of Artois, Flanders, Nevers, and Rethel. Philip died in 1404 and Margaret died the next year.
Her eldest son, John the Fearless, succeeded her in 1405 as duke of Burgundy, count of Burgundy, count of Artois, and count of Flanders. In 1406 her younger son Anthony inherited Brabant and Limburg.
East Flanders lies east and north-east of the western province, and extends northwards to the neighbourhood of Antwerp.
Margaret, however, ruled with a strong hand for many years and survived both her sons, dying at the age of eighty in 1280.
In his time the long contest between Flanders and Holland for the possession of the island of Zeeland was brought to an end by a treaty signed on the 6th of March 1323, by which West Zeeland was assigned to the count of Holland, the rest to the count of Flanders.
He was succeeded by his son, John III., " the Triumphant " (1312-1355), who succeeded in maintaining his position in spite of formidable risings in Louvain and Brussels, and a league formed against him by his princely neighbours, but he had a hard struggle to face, and many ups and downs of fortune.
The question had been compromised by the cession to Margaret in 1 347 of the margraviate of Antwerp by John III., but a war broke out in 1356 between Wenzel supported by the gilds, and Louis, who upheld the burgher-patrician party in the Brabant cities.
After his death (1383) his widow continued to rule over the two duchies for eighteen years, but was obliged to rely on the support of the house of Burgundy in her contests with the turbulent city gilds and with her neighbours, the dukes of Julich and Gelderland.