The largest, and most powerful of the Christian military orders, the Poor Knights of Christ and the Temple of Solomon, widely known as the Knights Templar, was founded in 1118, in the aftermath of the First Crusade, to help the new Kingdom of Jerusalem maintain itself against its hostile Muslim neighbors, and to ensure the safety of the large numbers of European pilgrims who flowed towards Jerusalem after its conquest.

Their popular name alludes to their historical headquarters in Qubbat es-Sakhrah (Dome of the Rock), an Islamic shrine on the summit of Mount Moriah in Jerusalem, which they renamed Templum Domini (Temple of the Lord). The summit is sacred to Jews and Christians as the Temple Mount as well as to Moslems as the Haram al-Sharif (Nobel Sanctuary). The Templars erroneously believed the Dome of the Rock to be remnants of the biblical First Temple of Jerusalem. The Templum Domini became the model for many subsequent Templar churches in Europe, such as the Temple Church in London and is represented on several Templar seals.

Places associated with the Knights Templar

•  Convento de Cristo, Castle of Tomar and Church of Santa Maria do Olival in Tomar, Portugal.
• Castle of Almourol, Idanha, Monsanto, Pombal and Zêzere in Portugal
• Castle of Soure, Coimbra in Portugal
• Kolossi Castle in Cyprus
• Temple Church in London
• Hertford, England as in the Guardian
• Holy Sepulchre in Cambridge Round Church
• St Sepulchre's in Northampton UK
• Rosslyn Chapel and Orphir Church in Scotland
• Temple Mount, Dome of the Rock, and Well of Souls in Jerusalem
• Chapel Chwarszczany in Poland
• La chapelle saint-Georges d'Ydes in France
• Church at Laon in France
• Round Church of Lanleff in Brittany, France
• The castle of Barberà in Spain
• The castle of Ponferrada in Spain
• Krak des Chevaliers (Castle of the Knights Hospitaller)
• Oak Island, Nova Scotia (fabled western outpost)
• Church of San Jacopo in Campo Corbolini, in Florence (Italy)