The Poor Fellow-Soldiers of Christ and of the Temple of Solomon, commonly known as the Knights Templar or the Order of the Temple, were among the most famous of the Western Christian military orders. Founded in the aftermath of the First Crusade of 1096, the Order's original purpose was to ensure the safety of the many Christians who made the pilgrimage to Jerusalem after its conquest. Officially endorsed by the Catholic Church around 1129, the Order became a favored charity throughout Christendom and grew rapidly in membership and power. Templar knights, in their distinctive white mantles with red crosses, 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 many fortifications throughout the Mediterranean and the Holy Land. When the Holy Land was lost, support for the Order faded. Rumors about the Templars' secret initiation ceremony created mistrust, and King Philip IV of France, deeply in debt to the Order, pressured Pope Clement V to take action against the Order. In 1307, many of the Order's members in France were arrested, tortured into giving false confessions and burned at the stake. In 1312, Pope Clement, under continuing pressure from King Philip, disbanded the Order. The abrupt disappearance of a major part of the societal infrastructure gave rise to speculation and legends, which have kept the Templar name alive into the modern day.

Wrapped in splendor and mystique, the Knights Templar had enermous power from the 12th to the 16th centuries. They arrived in Portugal in 1140 to expel the Moors, but after two centuries, Christians had recaptured Portugal and there was little demand for the knights' military skills. After Pope Clement V dissolved the Knights Templar in 1312, the Dom Dinis of Portugal followed the trend by disbanding the Order in 1314. A few years later he cannily re-established it as the Order of Christ, under the royal control. It was largely thanks to the Order's wealth that Prince Henry the Navigator, a Knights Templar Grand Master from 1417 to 1460, was able to fund the Portuguese Age of Discoveries. In 1160, the Portuguese Templar Grand Master, Gualdim Pais started the construction of a new Templar fortress in Tomar. Known today as the Convento de Cristo, the castle in Tomar was the Knights' Templar headquarters, and even today it is an expression of magnificence set in stone with exuberant theatricality that gave the order such an enduring fascination. Set on wooded slopes above the quaint town of Tomar and enclosed within 12th century walls is still a mystical and spiritual place.