The Kingdom of Jerusalem was a medieval state established in 1099 during the First Crusade. It was located in the region of the modern-day Middle East, primarily in what is now Israel and Palestine. The kingdom was founded after Christian forces captured the city of Jerusalem, which became its capital. The kingdom existed for nearly two centuries, facing constant threats from Muslim forces. It was ruled by a series of monarchs, including notable figures like Baldwin IV and Godfrey of Bouillon. The kingdom ultimately fell to the Muslim leader Saladin in 1187, marking a significant turning point in the Crusades.