Gregory, from a noble Roman family, from which also came Pope Saint Felix III, had transformed, in 575, before his election, his own house into a monastery with an adjoining church, dedicated to Saint Andrew the Apostle.
In the Early Middle Ages, a church dedicated to the holy pope arose in its place. This was completely renewed externally by Gian Battista Sorìa (staircase, facade, and atrium), and internally by Francesco Ferrari.
The facade rises at the top of the stairs, vigorously articulated on two orders of pilasters, which divide it into three bays, of which the central one is crowned by a pediment, a porch, and large balcony windows. The atrium is surrounded by porticoes and contains some interesting tombs such as that of Sir Edward Carne, a dignitary of the court of Henry VIII, sent in 1561 for the matter of the king’s divorce from his first wife Catherine of Aragon.
The interior presents itself in the Baroque appearance given by Ferrari. It has three naves divided by sixteen ancient columns and is decorated with pillars and stuccoes. The mosaics are also very interesting.
