The statue that crowns Spire G23 has been the focus of extensive debate regarding its iconography: the sources in Veneranda Fabbrica’s Archive indicate two possible identifications. In the features of the man looking up to heaven scholars have recently identified the martyr Tranquillino (from the Latin Tranquillus or “calm”), who lived in the 3rd century AD. Father of saints Mark and Marcellian of Rome, he was martyred while praying by the tomb of the apostle Paul, where pagans lapidated him and threw his body into the river Tiber.Other theories, instead, identify San Saturnino of Cagliari in the sculpture. He is highly venerated in Sardinia. Young Saturnino was beheaded for refusing to make sacrifices to the pagan gods in 304 AD, during Diocletian’s persecutions. But the story of the Passion of San Saturnino of Cagliari resembles that of another San Saturnino, bishop of Toulouse, and of St. Sergius. Other theories too have been brought forward, according to which San Saturnino was an African martyr venerated in Sardinia, considering the frequent contact between the island and the Mediterranean regions of the African continent. But it is hard to establish which African Saturnino he was, given the large number of martyrs with this name. San Saturnino is celebrated on 30 October especially in Cagliari where the relics of the city’s patron saint are preserved.