The original Charlemagne Roman Templar rotunda is built in two phases (1160-1190 and 1200-1250 with the cannon vault closure). The octagonal form of centralized plant comes from the influence of the first baptisteries and mausoleums of the Lower Empire, during the time of the Crusades the religious-military orders sought to reproduce the chancel of the basilica of the Holy Sepulcher of Jerusalem. In 1509 with the fall of a thunderbolt it loses the summit part a dome with openings, covered with glazed blue tile. With the governance of the Order of Christ by Infante D. Henrique (1417-1450) she receives a body for the west, which served as a high choir and tribune. The Cemetery and Washing Cloisters are from that time