During the eleventh and twelfth centuries the Church began a process of renovation (renovatio) and the city of Rome was given new meanings. Antiquity is part of the identity of the Eternal City; the reuse or reframing of aspects of antiquity inevitably transformed the image of Rome. Public spaces, architecture and objects were given new Christian readings. Inscriptions, present both in sacred and secular settings, played an important role. A similar rewriting can also be found in travel literature and descriptions of the city, such as in the Mirabilia urbis Rome, where ancient monuments were re-interpreted to demonstrate the superiority of Christianity. Inscriptions were used as symbols of authority, as can be seen in the altar of the church of Santa Maria in Portico, in the papal thrones (San Clemente, Santa Maria in Cosmedin, San Lorenzo fuori le mura) and also in mosaics (San Clemente, Santa Maria in Trastevere). Inscriptions appeared on porticoed atriums built on new churches and added to older foundations, and they were used to renew ancient monuments and places. The Roman Commune used a similar strategy with civil buildings. The image of Rome was transformed through restoration and new construction that used spolia as meaningful objects, and inscriptions for their authoritative value.