The kingdom of Jerusalem was founded as a consequence of the 1st crusade of 1099. Godefroi de Bouillon died in 1100 and was succeeded by his brother Baudoin I (+ 1118) and a great-nephew Baudoin II (+ 1131), who left an eldest daughter Mélissende. She passed the throne to her husband Foulques d'Anjou (+ 1147), and to her sons Baudoin III (+ 1163) and Amaury or Amalric (+ 1173). Amaury had a son and successor Baudoin IV (d. 1185), and two daughters, Sybille and Isabeau (1169-1206).
The arms of Jerusalem pop up in a number of places. The reason for this is the rather tortuous history of the throne and title. The short version is this: three lines stemmed from Queen Isabeau (d. 1206), the eldest of which ruled in absentia until 1268, at which time the two other lines entered in dispute over the succession. From this dispute stems the claims of (1) the kings of Cyprus and (2) the kings of Sicily. The claim to Cyprus (1) became object of dispute in 1474 as the result of an usurpation: the claims of the usurper (1a) passed to Venice, while those of the displaced ruler (1b) passed to Savoy. As for the claims of the kings of Sicily (2), it became part of the kingdom of Aragon. Then the claims passed along with Sicily itself to the kings of Spain (1506-1700). As a result of the war of Spanish Succession (1701-13), Naples and Sicily were ceded by Spain to the Habsburg emperor Charles VI in 1720, and the pope duly invested the emperor with the titles of king of Sicily and Jerusalem on June 5, 1722 (the kingdom being a papal fief). In the course of the war of Polish Succession (1733-38), the younger son of the king of Spain, Don Carlos, managed to conquer the Two Sicilies, a conquest recognized by the peace of Vienna of 1738, and by the pope in the same year. Carlos became king of Spain in 1759 and left Naples and Sicily to his younger son Ferdinand, whose descendants reigned until 1860. The kings of Spain continued to use the title of Jerusalem until 1931