Heque Nationale, Paris, France/Bridgeman Art Library

Poor Knights of Christ and the Temple of Solomon, or the Templars as they came to be known, are shown here besieging the city of Jerusalem in a 14th-century illuminated manuscript from the Book of Godfrey of Bouillon. Founded in 1119 the Templars’ initial purpose was to protect pilgrims traveling to the Holy Land. They eventually became one of the most successful fighting forces of the Crusader period. Their influence grew with their numbers and the wealth that they amassed in spite of their monastic vows of poverty and chastity. After the collapse of the crusader stronghold in the Holy Land in 1291, opposition to the Templar order from the pope and the king of France (the cause of which is a matter of debate among historians), led to their condemnation and systematic persecution, reaching its peak with the execution of the last Grand Master of the order, Jacques de Molay, who was burned at the stake in 1314.