the Iberian Union (1581–1640), during which the Crowns of Portugal and Spain were united in a dynastic union. The aqueduct of the Convent was built during this period (aqueduct completed in 1614). Architecture The castle and Convent of Christ have examples of Romanesque, Gothic, Manueline and Renaissance architectural styles. Castle The castle of Tomar was built around 1160 on a strategic location, over a hill and near river Nabão. It has an outer defensive wall and a citadel (alcáçova) with a keep inside. The Keep, a central tower of residential and defensive functions, was introduced in Portugal by the Templars, and the one in Tomar is one of the oldest in the country. Another novelty introduced in Portugal by the Templars (learned from decades of experience in Normandy and Brittany and elsewhere) are the round towers in the outer walls, which are more resistant to attacks than square towers. When the town was founded, most of its residents lived in dwellings located inside the protective outer walls of the castle. Church The Romanesque round church is a Catholic Church from the castle (charola, rotunda) was built in the second half of the 12th century by the Knights Templar. From the outside, the church is a 16-side polygonal structure, with strong buttresses, round windows and a bell-tower. Inside, the round church has a central, octagonal structure, connected by arches to a surrounding gallery (ambulatory). The general shape of the church is modelled after similar round structures in Jerusalem: the Mosque of Omar and the Church of the Holy Sepulchre. The capitals of the columns are still Romanesque (end of the 12th century) and depict vegetal and animal motifs, as well as a Daniel in the Lions' Den scene. The style of the capitals shows the influence of artists working on the Cathedral of Coimbra, which was being built at the same time as the round church. The interior of the round church is magnificently decorated with late gothic/manueline sculpture and paintings, added during a renovation sponsored by King Manuel I starting in 1499. The pillars of the central octagon and the walls of the ambulatory have polychrome statues of saints and angels under exuberant Gothic canopies, while the walls and ceilings of the ambulatory are painted with Gothic patterns and panels depicting the life of Christ. The paintings are attributed to the workshop of the court painter of Manuel I, the