Between 320 and 327, Constantine built a five-aisled basilica atop the early Christian necropolis that was purported to be Peter's resting place. Much of the Vatican Hill was leveled to provide a firm foundation for the first St. Peter's Basilica. The altar of the Basilica was planned to be located directly over the tomb. The matter was complicated by the upper chamber or memoria above the vault. This upper chamber had become endeared to the Romans during the ages of persecution, and they were unwilling that it should be destroyed. The memoria was turned into the Chapel of the Confession. Above that was the main floor of the Basilica, with the raised altar directly over the Chapel of the Confession.