Joan, often called Joan of Constantinople (c. 1199 – 5 December 1244), was the countess of Flanders and Hainaut from 1205 (at the age of six) until her death. She was the elder daughter of Baldwin IX, Count of Flanders and Hainaut, and Marie of Champagne.
Orphaned during the Fourth Crusade, Joan was raised in Paris under the tutelage of King Philip II of France. He arranged her marriage to Infante Ferdinand of Portugal in 1212. Ferdinand quickly turned against Philip, starting a war that ended with the defeat of Bouvines and his imprisonment. Joan then ruled her counties alone from the age of 14. She faced the rivalry of her younger sister, Margaret, as well as the revolt of her domains – guided by a man who claimed to be her father. After the end of the war, Ferdinand was released but died soon after. Joan then married Thomas of Savoy. She died in 1244 at the Abbey of Marquette near Lille, having survived her only child, a daughter by Ferdinand.
Joan's policies favored economic development in her counties; in fact, she granted several charters to the Flemish cities. She played an important role in the development of the Mendicant orders, the Beguines, the Victorines and hospital communities in her domains (without neglecting the traditional religious orders). Under her reign, women's foundations increased, transforming the place of women in both society and the church.
The Manessier's Continuation (also called the Third Continuation), one of the novels of the Story of the Grail was written for Joan, as well as the Life of St. Martha of Wauchier de Denain. The first novel in Dutch, Van den vos Reynaerde, was written by a cleric of her court.
There are several painted or sculpted representations of the Countess in France and Belgium, as well as two Géants du Nord.
Joan's exact date of birth is unknown. Contemporary sources indicate that, like her younger sister Margaret, she was baptized in the Church of St. John of Valenciennes.
In 1202, Joan's father, Baldwin IX, left his lands to participate in the Fourth Crusade. After the capture of Constantinople, he was proclaimed emperor by the crusaders on 9 May 1204. Her mother, Marie of Champagne, decided to join him shortly after his departure, leaving their daughters Joan and Margaret in the care of their paternal uncle, Philip I of Namur. Marie decided to make a pilgrimage to the Holy Land before reuniting with her husband, but died after her arrival at Acre in August 1204. One year later, on 14 April 1205, Baldwin vanished during the Battle of Adrianople against Bulgarians and Cumans under Tsar Kaloyan of Bulgaria. His fate is unknown.
After the news of Baldwin's disappearance reached Flanders in February 1206, Joan succeeded her father as countess of Flanders and Hainaut. Because she was still a child, the administration of both counties was assumed by a council composed of the chancellor of Flanders, the provost of Lille and the castellans of Lille and Saint-Omer.
The guardianship and education of both Joan and her sister was supervised by their uncle Philip, who soon put his nieces in a difficult position. He became betrothed to Marie, a daughter of King Philip II of France. He gave his future father-in-law custody of Joan and Margaret, who were raised in Paris alongside the young Count Theobald IV of Champagne. During their time in France, they became familiar with the Cistercian Order, probably because of the future French queen Blanche of Castile.
In 1206, the French king demanded assurances from Philip I of Namur that he would not marry off his nieces without the former's consent. In 1208, they reached an agreement: Joan and Margaret were forbidden to marry before their legal majority without the consent of the Marquis of Namur. However, the Marquis would not oppose the royal choice of husbands. If either refused the candidate chosen by King Philip II, the agreement required the Marquis to find a husband—after compensation was made to the French king.
In 1211 Enguerrand III of Coucy offered the King the sum of 50,000 livres to marry Joan, while his brother Thomas would marry Margaret. However, the Flemish nobility was hostile to the project. Matilda of Portugal, widow of Joan's granduncle Philip I of Flanders, then offered her nephew, Ferdinand of Portugal, as Joan's husband for the same amount. The marriage was celebrated in Paris in January 1212. Ferdinand thus became Joan's co-ruler.
While on their way to Flanders, the newlyweds were captured by Joan's first cousin Louis of France (the future Louis VIII), eldest son of King Philip II. The French prince intended to recover a large portion of the territory that he considered as belonging to his late mother's dowry, including the Artois that Joan's father had taken back by force after the death of Louis' mother in 1190.
Joan and Ferdinand only could obtain their release after signing the Treaty of Pont-à-Vendin (25 February 1212), under which they were forced to surrender the towns of Aire-sur-la-Lys and Saint-Omer to France, recognizing the previous occupation of Prince Louis over those lands. After this event, Joan and Ferdinand decided to join in an alliance with the former allies of Baldwin IX, King John of England and Otto IV, Holy Roman Emperor. They obtained the support of the powerful bourgeoisie of Ghent (who initially refused to recognize Ferdinand as Count) after Joan and Ferdinand agreed to the annual election of four prudhommes chosen among the aldermen of the city; the granting to the people of Ghent and Ypres of permission to fortify their cities; and the resignation of the castellans of Bruges and Ghent, deemed pro-French.
In retaliation for this alliance, King Philip II attacked Lille, which was burned (with the exception of the fortified castrum and churches) in 1213. In Damme, the French fleet was destroyed by the English. At the Battle of Roche-au-Moine (2 July 1214), Prince Louis defeated the English army. Then King Philip II inflicted upon his opponents a decisive defeat at the Battle of Bouvines (27 July 1214), where Ferdinand was captured. During the twelve years that followed, while Ferdinand remained a prisoner of the French, Joan governed alone.
One of her first rulings was to exempt certain groups from taxes to encourage industry: an example is that of settlers in Kortrijk, who did not have to pay property tax, to promote woollen weaving in the town. Also she ordered the reconstruction of Lille's ramparts, but fearing a new French offensive, she eventually was forced to sign the Treaty of Paris (24 October 1214), under which major fortresses in southern Flanders were destroyed; property was restored to French partisans; and Flanders was in effect ruled from Paris.
In the meanwhile, the Countess began to petition the Pope for the annulment of her marriage, arguing that it had never been consummated. In 1221, she sought to marry Peter Mauclerc (Duke-Regent of Brittany and widower of Alix of Thouars) but King Philip II refused.
Before 23 July 1212, Joan's younger sister Margaret married Bouchard of Avesnes, Lord of Etroen. The French King, viewing this union with suspicion, informed Pope Innocent III that Bouchard before his wedding had already taken holy orders as sub-deacon. In 1215, at the Fourth Lateran Council, the Pope annulled the marriage on this ground. Margaret and Bouchard, however, refused to submit. They took refuge at the Castle of Houffalize in the Ardennes under the protection of Waleran, Count of Luxembourg. In the following four years, they had three sons: Baldwin (who died in infancy), John and Baldwin.
In 1219, during a battle in Flanders against Joan, Bouchard was captured and imprisoned. Two years later (1221), he was released after agreeing to separation from his wife. Between 18 August and 15 November 1223, Margaret married William II of Dampierre.