In about 1080, in Chartres, France, Stephen married Adela, a daughter of William the Conqueror. Their third son Stephen of Blois became king of England after Henry I of England died without a male heir and the English did not think Henry I's daughter Empress Maud a suitable ruler because of her sex.
Count Stephen was one of the leaders of the First Crusade, often writing enthusiastic letters to Adela about the crusade's progress. He returned home in 1098 after the lengthy siege of Antioch, without having fulfilled his crusading vow, which would have been completed only if he had made it all the way to Jerusalem. He was pressured by Adela into making a second pilgrimage, and along with others who faced the same pressures after returning home prematurely, he joined the minor crusade of 1101. In 1102, Stephen was killed in battle at the age of 57, during the Crusader Kingdom of Jerusalem's siege of Ascalon in what is now Israel.