His career was as a knight in royal service, though not with the kings of his native France but with their English opponents. In 1170, still in his teens, he was with his lifelong friend,
William Marshal in the court of
Henry the Young King. In 1180 at the great international
tournament of
Lagny-sur-Marne, he was a
knight banneret, leading the Flemish team while William headed the English team. About 1187, he was rewarded with his first landholding in England and, once king,
Richard I of England added the lordship of several other manors. These not only gave him income but also, at least as important in those times, added to his rank of knight the status of a feudal landowner. In 1191 he was with Richard's contingent on the
Third Crusade in
Palestine where his father Robert, who was with the Flemish contingent, died. When Richard set out on his incognito voyage home in 1192, Baldwin was with him. They were blown ashore in a December storm near
Aquileia and the disguised Richard was captured by his Austrian enemies at an inn near
Vienna. Baldwin stood hostage for him, let loose to organise a
ransom into which he put not only months of effort but much of his own money as well. As well as cash to free Richard,
Leopold V, Duke of Austria wanted two princesses, including
Eleanor, niece of Richard. Early in December 1194, Baldwin was sent with two princesses to Vienna and told that if he did not turn up with them his life would be forfeit. Before they arrived, the Duke died and with him the death threat. In 1195 Baldwin married Hawise of Aumale, a great Anglo-Norman heiress, gaining through his wife vast lands and the title of Count of Aumale. The lands of
Aumale itself were however lost shortly after in 1196, when the French captured and kept them. In 1197 Baldwin was one of the English delegates to the election of Richard's nephew
Otto IV of Germany as
Holy Roman Emperor. When
John succeeded Richard as king in 1199, Baldwin was initially in his immediate circle. In 1200 he was one of John's guarantors for the peace signed with the French king,
Philip and the next year he was one of the signatories to a royal grant. After that he seems to have become less close to the king and no doubt occupied himself with running both his wife's and his own extensive estates in England. On 13 or 14 October 1212 he died, probably in Hawise's house at
Burstwick in Yorkshire, and was buried in the chapter house at
Meaux Abbey, of which nothing remains. On 3 November 1212, Hawise promised the king 5000 marks (£3333 then, equivalent to over £3 million in 2014) to keep her lands and avoid a fourth marriage. On the death of his father in 1199 he had become Advocate of the Abbey of Chocques and guaranteed its rights and privileges. After he died, in memory of his donations, the abbot and monks prayed daily for his soul and held a solemn mass on the anniversary of his death. ==Marriage and family==