The Kingdom of Jerusalem came into existence due to crusaders. Pope Urban II called for the First Crusade in 1095 to assist the Byzantine Empire against the invasions of the Seljuk Turks. The ultimate goal was to control the Holy Land. After successfully laying siege to Jerusalem in 1099, Godfrey of Bouillon, who had been one of the leaders of the First Crusade, became the first ruler of the Kingdom of Jerusalem under the title Defender of the Holy Sepulchre. He increased the boundaries of the new Kingdom by capturing the towns of Jaffa, Haifa and Tiberias. He also established the Principality of Galilee and the County of Jaffa. He died in 1100 of an illness.
His brother Baldwin of Boulogne claimed the Kingdom for himself, and he was crowned as the first King of Jerusalem. He expanded the Kingdom even further and successfully defended himself against Muslim invasions. Although he had married thrice (even bigamously), he had no heirs upon his death in 1118. The Kingdom was offered to his brother Eustace III of Boulogne, but he refused the offer. It was offered to another relative Baldwin of Le Bourg, who succeeded him as King Baldwin II. The earliest written laws date from his reign. Baldwin and his wife Morphia of Melitene had four daughters, including Melisende who would succeed him upon his death in 1131. Melisende’s husband Fulk V of Anjou was her King-consort, and their son Baldwin III was named as a co-heir by his grandfather.
In 1144, Edessa was invaded and conquered to the shock of Europe and prompted the arrival of the Second Crusade in 1148. The subsequent Siege of Damascus failed, and the crusading armies returned home. This failure meant that no large-scale expeditions would return to the Kingdom and an internal squabble between Melisende and her son, led to Baldwin having himself crowned as sole ruler. The Kingdom was effectively split in two. Baldwin attacked his mother’s lands, forcing her to surrender. Baldwin allied himself with the Byzantine Empire by marrying a niece of the Emperor, Theodora Komnena. They had no children, and upon his death in 1162, the Kingdom passed to his brother Amalric. He too married a niece of the Emperor, Maria Komnene. They had two children, of which one daughter survived to adulthood. She was the future Isabella I of Jerusalem. He had been married once before and had a surviving son and daughter, the future Baldwin IV and Queen Sibylla. Baldwin succeeded him upon his death in 1174. However, Baldwin suffered from leprosy and did not have any children.
His full sister Sibylla married William of Montferrat, who was a relative of both the King of France and the Holy Roman Emperor. They had a son, yet another Baldwin, who the elder Baldwin had crowned co-King at the age of 5. The elder Baldwin proved to be an inspirational King, despite his illness. He died in 1185, and the younger Baldwin succeeded as sole King as Baldwin V. He died just one year later at the age of 9. It was unclear who would succeed now. Baldwin V’s mother was the most obvious heir but her second husband, Guy of Lusignan, was most unpopular. She was offered the crown on the condition that her marriage was annulled. She agreed on the condition that she be allowed to choose her own husband and King. After being crowned, she immediately crowned her husband. Sibylla and her two young daughters from her second marriage died in an epidemic that swept through their military camp.
By then most of the Kingdom had been overrun by Saladin, the Sultan of Egypt and Syria. The army was destroyed at the Battle of Hattin in 1187. The fall of Jerusalem ended the first Kingdom of Jerusalem, but this led to the Third Crusade which was launched in 1189. It was led by Richard the Lionheart, Philip II of France and Frederick I, Holy Roman Emperor (who drowned en route).
Sibylla’s legal heir was her sister, Isabella, although Guy attempted to keep his hold on the crown. Isabella was married four times and had seven children from three husbands. Her only son died young. Richard the Lionheart defeated Saladin in two separate battles but failed to recover Jerusalem. The Third Crusade ended with the Treaty of Ramla and Saladin allowed pilgrimages to be made to Jerusalem. The Kingdom began to be rebuilt from Acre on the coast. It was now just a tiny Kingdom on the coastline.
When Isabella died in 1205, she was succeeded by her eldest daughter Maria. She was a minor and was under the regency of her uncle, John of Ibelin until 1210 when she married John of Brienne. She died in childbirth just two years, and John continued ruled as regent for their young daughter Queen Isabella II. A Fourth and Fifth Crusade failed to bring success and John could only find help with Frederick II, Holy Roman Emperor, who married Isabella in 1225. Isabella died in 1128 giving birth to their only child, a son named Conrad. Frederick arrived with a Sixth Crusade and claimed the regency in the name of his son. The Kingdom slowly returned to a bit of its former glory. Conrad died in 1254 and was succeeded by his two-year-old son, Conradin.
Just 14 years later, the young King was imprisoned and executed while on a military campaign. He had no direct heir, and the claim passed to the heirs of Queen Isabella I. The senior claim by primogeniture was Hugh of Brienne, but another cousin Hugh III of Cyprus already held the regency in Jerusalem and managed to keep the crown as King Hugh I of Jerusalem. He was the great-grandson of Isabella I through his mother. He left for Cyprus after finding the Kingdom unmanageable due to his unpopularity, and he never managed to return as its King. After his death in 1284, he was briefly succeeded by his son, John II, who died the following year. He was succeeded by his brother, Henry II. Soon the Kingdom began to fall apart yet again. By 1303, there was no more Kingdom of Jerusalem on the mainland.
For several centuries the Kings of Cyprus planned to retake the territories they had lost, but they were never successful. The title of King of Jerusalem is claimed by several people. The senior line of Hugh of Brienne eventually merged with the Hugh III of Cyprus claim and both are represented by Prince Charles-Antoine Lamoral of Ligne-La Trémoïlle.
Today the Kingdom of Jerusalem lies in Cyprus, Israel, Palestine, Jordan and Lebanon. 1