A useful bit of trivia for your next pub quiz: King Juan Carlos also happens to be the King of Jerusalem, although I don’t know if anyone has told the Israelis.
His Majesty Juan Carlos the First, By the Grace of God, the King of Spain, King of Castile, of León, of Aragon, of the Two Sicilies, of Jerusalem, of Navarre, of Granada, of Seville, of Toledo, of Valencia, of Galicia, of Sardinia, of Córdoba, of Corsica, of Murcia, of Jaén, of the Algarves, of Algeciras, of the Canary Islands, of the East and West Indies, of the Islands and Mainland of the Ocean Sea; Archduke of Austria; Duke of Burgundy, of Brabant, of Milan, of Athens and Neopatria; Count of Habsburg, of Flanders, of Tyrol, of Roussillon, and of Barcelona; Lord of Biscay and of Molina de Aragón; Captain General and Supreme Commander of the Royal Armed Forces; Sovereign Grand Master of the Order of the Golden Fleece and of the orders awarded by the Spanish state, inherits the title through the Kingdom of Naples.
Back in the 1095 Holy Crusade, that canny old French knight Balduin got Pope Urban II to recognise him as the ruler of the conquered region and, in 1099, declared himself to be King of Jerusalem.
Things got messy during the next hundred years, and the Kingdom was mainly ruled down the female line, through a succession of Queens, as sons and husbands kept getting mown down by the irate Muslims. Eventually the line fled back to Europe, leaving Jerusalem in the hands on the Muslims. However, in order to keep the flame of Christianity burning, the Royal Line continued with papal assent, in the hope of unifying the various crusades that were taking place.
Queen Elizabeth II (1221-1228) saw an opportunity to get hitched to the Holy Roman Emperor of the time, Frederick II, and gave him the title. Frederick was sufficiently tickled by the title to send an army on whichever Crusade was happening that year (the Fifth, although this doesn’t take into account the many failed ones that never got Numbered), and managed to reconquer the city, about a hundred years after the Christians had been kicked out.
The HRE held it from 1229 to 1244, when the Muslims finally managed to get them out. The city never returned to Christian hands (or, at least, not for very long) but the title continued, linked to the HRE. IN fact, the last Christian bastion of Acra was razed in 1291, killing off the Kingdom. The title became virtual, with no lands.
Things carried on until 1510, when the title had been passed to the maniac Alfonso de Anjou, joint King of Naples and King of Jerusalem. Alfonso royally annoyed King Fernando “el católico” of Spain, who in that year sent his “great captain” Gonzalo Fernando de Córdoba to conquer Naples, which he did, and returned to Spain with the titles for his King.
Strangely enough, the title very nearly passed to the Tudor line in England – Carlos V was about to bestow the title on Felipe II when he became engaged to Mary Tudor, Queen of England. When Mary lost her head, the wedding was called off and the title returned to Carlos V.
It’s remained with the Kings of Spain ever since, meaning that old Juancar is still, in name alone, King of Jerusalem.