Passage: The cathedral was founded probably in the 5th or 6th century AD, devoted to Saint Sirus, bishop of Genoa. Excavations under the pavement and in the area in front of today's west front have brought to light walls and pavements of Roman age as well as pre-Christian sarcophagi, suggesting the existence of a burial ground in the site. Later a church devoted to the Twelve Apostles was built, which was in turn flanked and replaced by a new cathedral dedicated to Saint Lawrence, in Romanesque style. Money came from the successful enterprises of the Genoese fleets in the Crusades.

Question: What was the first age referenced?
Roman age