Gregory, from a noble Roman family, which also included Pope Saint Felix III, had transformed his own house into a monastery with an attached church dedicated to Saint Andrew the Apostle in 575, before his election.
In the Early Middle Ages, a church dedicated to the holy pope was built in its place. This was completely renovated externally by Gian Battista Sorìa (stairs, facade, and atrium), and internally by Francesco Ferrari.
The facade rises at the top of the stairway, strongly articulated into two orders of pilasters, which divide it into three bays, the central one crowned by a pediment, a portico, 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 regarding the king’s divorce from his first wife Catherine of Aragon.
The interior presents a baroque appearance given by Ferrari. It has three naves divided by sixteen ancient columns and is decorated with pilasters and stuccoes. The mosaics are also very interesting.
