' (half-
denarius or
petit denier) struck at
Ypres under Baldwin IX Baldwin took possession of a much-reduced
Flanders, lessened by the large chunk, including
Artois, given by Philip of Alsace as dowry to Baldwin's sister
Isabelle of Hainaut, and another significant piece to his own wife. Isabelle had died in 1190, but King Philip still retained her dowry, on behalf of Isabelle's son, the future
Louis VIII of France. The eight years of Baldwin's rule in Flanders were dominated by his attempts to recover some of this land. After
Philip II of France took Baldwin's brother, Philippe of Namur, prisoner, Baldwin was forced to agree to a truce to ensure his safety. The Treaty of Péronne was signed in January 1200 on the condition that Baldwin receive the territories he had won during the war. Baldwin was made the
vassal of Philip II, and the king returned portions of
Artois to Baldwin. In this fight against the French king, Baldwin allied with others who had quarrels with Philip, including kings
Richard I and
John of England, and the
German King Otto IV. A month after the treaty, on
Ash Wednesday (23 February) 1200 in the town of
Bruges, Baldwin '
took the cross', meaning he committed to embark on a
crusade, namely the
Fourth Crusade. He spent the next two years preparing, finally leaving on 14 April 1202. As part of his effort to leave his domains in good order, Baldwin issued two notable charters for
Hainaut. One detailed an extensive criminal code and appears to be based on a now-lost charter of his father. The other laid down specific rules for inheritance. These are an important part of the legal tradition in Belgium. Baldwin left behind his two-year-old daughter and his pregnant wife, Countess Marie. Marie was regent for Baldwin for the two years she remained in Flanders and Hainaut, but by early 1204, she had left both her children behind to join him in the East. They expected to return in a couple of years, but in the end, neither would see their children or their homeland again. In their absence, Baldwin's younger brother
Philip of Namur was regent in Flanders, with custody of the daughters. Baldwin's uncle William of Thy (an illegitimate son of
Baldwin IV of Hainaut) was regent for Hainaut. Meanwhile, desperate for funds to support themselves and pay for their expenses, the leaders of the Fourth Crusade were persuaded by the
Venetians (who had built the crusaders' fleet) to divert to
Constantinople. The Venetians had had designs on the Byzantine capital for some time, and also wished to revenge themselves for the
Massacre of the Latins in 1182. The political excuse for this excursion was in large part due to the exiled Byzantine prince Alexios (the future Emperor
Alexios IV Angelos), who promised the crusaders supplies, money, and the island of
Crete in return for their help in ousting his uncle Emperor
Alexios III Angelos and freeing his imprisoned father
Isaac II Angelus. In April 1204, after numerous failed negotiations attempting to obtain the promised funds from the Byzantines, the Crusaders
conquered the most powerfully protected city in the world. Stunned at their own success and unsure of what to do next, the leaders adopted a similar track as their forefathers had during the First Crusade. They elected one of their own, Count Baldwin of Flanders as emperor (of what modern historians refer to as the
Latin Empire) and divided imperial lands into feudal counties. ==Latin emperor==