Baldwin was born in 1130 to Fulk of Jerusalem and Melisende of Jerusalem, and he came from the Catholic French House of Anjou. Baldwin succeeded his father as king of Jerusalem after his death in a hunting accident, and he ruled jointly with his mother until 1153. The County of Tripoli, County of Edessa, and the Principality of Antioch asserted their independence from Jerusalem with a woman and a child ruling the powerful Kingdom of Jerusalem, and he also had to deal with the advances of Zengi and the Zengids, who took Edessa in 1144. Zengi was assassinated in 1146, but his son Nur ad-Din became a great conqueror like his father. In 1148, the Second Crusade began as crusaders from France and the Holy Roman Empire arrived to assist the crusaders in regaining control of Edessa from the Muslims. Baldwin unwisely chose to attack Damascus, enemies of Nur ad-Din, rather than court their friendship, and the Muslims defeated the Christians. The Second Crusade failed, and Damascus fell to Nur ad-Din in 1154. In 1153 Baldwin overthrew his mother and became the sole ruler of Jerusalem, although she retained a large amount of influence in the court. That same year, he conquered Ascalon from the Muslims, and in 1157 he allied with the Byzantine Empire. He married Theodora Komnene, the niece of Manuel I of Byzantium in 1161, but he died in 1163.