The Poor Fellow-Soldiers of Christ and of the Temple of Solomon, commonly known as the Knights Templar, the Order of Solomon's Temple or simply as Templars, were among the most wealthy and powerful of the Western Christian military orders and were prominent actors in Christian finance. The organization existed for nearly two centuries during the Middle Ages.

Officially endorsed by the Roman Catholic Church around 1129, the Order became a favoured charity throughout Christendom and grew rapidly in membership and power. Templar knights, in their distinctive white mantles with a red cross, were among the most skilled fighting units of the Crusades. Non-combatant members of the Order managed a large economic infrastructure throughout Christendom, innovating financial techniques that were an early form of banking, and building fortifications across Europe and the Holy Land.

The Templars' existence was tied closely to the Crusades; when the Holy Land was lost, support for the Order faded. Rumours about the Templars' secret initiation ceremony created distrust, and King Philip IV of France, deeply in debt to the Order, took advantage of the situation. In 1307, many of the Order's members in France were arrested, tortured into giving false confessions, and then burned at the stake. Under pressure from King Philip, Pope Clement V disbanded the Order in 1312. The abrupt disappearance of a major part of the European infrastructure gave rise to speculation and legends, which have kept the "Templar" name alive into the modern day.