On 8 July 1290 Margaret married
John II, Duke of Brabant in
Westminster Abbey,
London, becoming
Duchess of Brabant less than four years later on 3 May 1294. She had been acquainted with her groom since childhood, as they had been betrothed in 1278 when she was three years old. Margaret's wedding festivities were splendidly extravagant; they included a procession of knights in full body armour and richly dressed ladies singing as they paraded through the streets of London to the music provided by harpers, minstrels and violinists, while fools danced. Their only child was
John III, Duke of Brabant, successor to his father. Margaret, described as having been a good-natured, merry child in her youth, was unhappy at the Brabant court, as she was forced to accept her husband's perennial succession of mistresses and the illegitimate children they bore him, all of whom were raised at court alongside her own son John. The latter was her only child, born 10 years into her marriage to the Duke. During the reign of John II,
Brabant continued supporting a coalition to stop French expansion. He tried to conquer South
Holland from the pro-French count
John II of Holland, but was not successful. Margaret and John attended the wedding of her brother Edward to
Isabella of France in
Boulogne on 25 January 1308. They accompanied the royal pair to England for their joint coronation at Westminster Abbey the following month. ==Later life and death==