# House of Flanders

The House of Flanders, also called the Baldwins (Latin: Balduini, French: Baudouinides, Dutch: Boudewijns), was a medieval ruling family of Frankish origin that was founded by Baldwin Iron Arm, son-in-law of Charles the Bald. The House of Flanders was the first dynasty to transform a county function of the Carolingian Empire into a hereditary fiefdom, the County of Flanders, falling under West Francia, created by the Treaty of Verdun in 843.
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 family had a series of setbacks, but in 1191, the family 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, and it also briefly ruled 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.

## Rulers
### Baldwinid dynasty
#### Partitions under Baldwinid dynasty

| | | Hainaut under House of Reginar rule (c.900-1051) | Namur under House of Namur rule (946-1189) |
| County of Boulogne (918-1152) | County of Flanders (862-1119) | Hainaut under House of Reginar rule (c.900-1051) | Namur under House of Namur rule (946-1189) |
| County of Boulogne (918-1152) | | County of Hainaut (1070-1194) | Namur under House of Namur rule (946-1189) |
| Boulogne inherited by the House of Blois | Inherited by the Estridsen, Normandy and Lorraine/Metz dynasties (1119-1194) | | |
| Boulogne inherited by the House of Blois | County of Flanders (1194-1280) (Hainaut branch) | County of Flanders (1194-1280) (Hainaut branch) | Marquisate of Namur (1205-1219) |
| Boulogne inherited by the House of Blois | County of Flanders (1194-1280) (Hainaut branch) | County of Flanders (1194-1280) (Hainaut branch) | Inherited by the House of Courtenay |
| Inherited by the House of Courtenay ||

## Genealogy

* Baldwin Iron Arm, Count of Flanders († 879)
** Baldwin II the Bald, Count of Flanders († 918)
*** Arnulf I the Great, Count of Flanders († 965)
**** Elftrude, born circa 932, married in 964 to Siegfried, Count of Guînes († 965)
**** Hildegarde (934 † 990), married in 943 to Dirk II, Count of Holland (930 † 988)
**** Egbert (937 † 953)
**** Liutgarde (938 † 964), married in 950 to Wichmann IV, Count of Hamaland and Ghent.
**** Baldwin III, Count of Flanders († 962)
***** Arnulf II, Count of Flanders († 988)
****** Mathilda († 995 or before)
****** Baldwin IV the Bearded (v.980 † 1035), Count of Flanders († 1035)
******* Baldwin V of Lille, Count of Flanders († 1067)
******** Baldwin VI the Good, (1030 - 1070), Count of Flanders and of Hainaut
********* Arnulf III of Flanders (1055 † 1071), Count of Flanders and Hainaut
********* Baldwin II of Hainaut (1056 † 1098), Count of Hainaut
********** Baldwin III of Hainaut (1088 † 1120), Count of Hainaut
*********** Baldwin IV the Builder (1108 † 1171), Count of Hainaut
************ Agnes of Hainaut, married Ralph I, Lord of Coucy
************ Baldwin V of Hainaut (1150 † 1195), Count of Hainaut
************* Isabella of Hainault (°1170- †1190), married Philip II of France
************* Baldwin VI of Hainaut (°1171- †1205), Count of Flanders and Hainaut, Latin Emperor of Constantinople
************** Joan (1199-1200 † 1244), Countess of Flanders and of Hainaut
************** Margaret II (c. 1202 † 1280), Countess of Flanders and of Hainaut
************* Yolanda (°1175- †1219), married Peter II of Courtenay, Latin Emperor of Constantinople
************* Philip the Noble, Marquis of Namur (°1175- †1212)
************* Henry (°1176- †1216), Latin Emperor of Constantinople
************* Sybille (°1179- †1217), married to Guichard IV, Sire of Beaujeu
************* Eustace (†1217), regent of the Kingdom of Thessalonica
******** Matilda (1032 - 1083), married in 1053 to William the Conqueror
******** Robert the Frisian, (1033 - 1093), Count of Flanders from 1071 to 1093
********* Robert II, Count of Flanders from 1093 to 1111
********** Baldwin VII (1093-1119), Count of Flanders
********** Guillaume (1094-1109)
********** Philip (1095-) (died young)
********* Adela of Flanders († 1115), married firstly Canute IV of Denmark. Married secondly Roger Borsa, Duke of Apulia.
********** Charles I, Count of Flanders (1084 – 1127)
********* Gertrude (1080 - † 1117), married to Henry III († 1095) Count of Louvain and Brussels, then in 1096 to Theodoric II, Duke of Lorraine († 1115).
********* Philip of Loo, whose illegitimate son William of Ypres was a claimant to the county of Flanders.
********* Ogive, abbess of Mesen.
******* Judith of Flanders, Countess of Northumbria (1037 † 1094), married in 1058 to Tostig Godwinson († 1066), Earl of Northumbria, then in 1071 to Welf I, Duke of Bavaria († 1101)
*** Adelolf († 933), Count of Boulogne
**** Arnulf II († 971), Count of Boulogne
***** Arnulf III († 990), Count of Boulogne
****** Baldwin II († 1025), Count of Boulogne
******* Eustace I (v. 995 † 1049), Count of Boulogne
******** Eustace II († 1087), Count of Boulogne
********* Eustace III, Count of Boulogne (1056 † 1125)
********** Matilda I, Countess of Boulogne (1105 † 1152), married in 1125 to Stephen of England
********* Godfrey of Bouillon (1058 † 1099), Duke of Lower Lorraine, a leader of the First Crusade and "Advocate of the Holy Sepulchre"
********* Baldwin I of Jerusalem (1065 † 1118), accompanied his brother to the Holy Land, became Count of Edessa and then King of Jerusalem
******** Godfrey († 1095), Bishop of Paris
******** Lambert II, Count of Lens († 1054)
******** Gerberge († 1049), married Frederick, Duke of Lower Lorraine (1003 † 1065)
****** Arnulf IV, Count of Ternois