The church of San Martino ai Monti has the relics of Pope-St. Martin I (†655) beneath the high altar. In the crypt are relics of Sts. Sylvester I (†337), Sergius I, Fabian, Stephen I, Soter, Cyriacus, Anastasius, Innocent I, Sergius II (†847), and some of St. Giuseppe-Maria de Tommasi. There are also relics of many early martyrs ‘known only to God’, as an inscription in the church says. Besides these, the throne of Pope-St. Sylvester is preserved as is his miter, Sylvester being the first Latin bishop to use a miter. This miter is the oldest one known to exist. This church was the site of preparatory meetings for the Council of Nicea (325) and was the first place in Rome that the Nicene Creed was proclaimed. Following the event, heretical books of Arius, Sabellius, and Victorius were burnt.