Rebuilt between the 12th and 14th centuries on the site of a Benedictine abbey dating from 960, this is the most important religious building from the medieval era in Genoa, together with the San Siro abbey. The beautiful Romanesque apse is of particular interest as is the crypt with five naves, which encircle theremains of a primitive, Longobard church dedicated to S. Michele, who according to tradition was baptised as Christopher Columbus here. His father was a warden of the nearby urban port of Olivella. The Roman-Gothis facade has black and white stripes and is clearly visible from Via XX Settembre. The interior, has an elevated presbytery, and is rather simple and severe. It is dominated by the large painting of the Martyrdom of San Stefano by Giulio Romano, which has slight damage from the bombings of the second world war.