House of Flanders

The House of Flanders—also called "the Baldwins" (, )—was a medieval ruling family founded by Baldwin I Iron Arm, son-in-law of Charles the Bald.
From 1051, the House of Flanders also reigned over the County of Hainaut, with Baldwin I of Hainaut. In 1119, on the death of Baldwin VII, the House of Flanders had a series of setbacks but in 1191, the House of Flanders recovered the title of Count of Flanders with Baldwin VIII (Baldwin V of Hainaut). The dynasty established the Latin Empire of Constantinople during the Fourth Crusade. It also ruled briefly the County of Namur (1188-1212). The House of Flanders became extinct in 1280 with the death of Margaret II.
A cadet branch, the House of Boulogne, ruled over the County of Boulogne. Members of this house joined the First Crusade, established the Kingdom of Jerusalem, and produced its first kings.