Pope Stephen II
The church traced its origins to an ancient square structure that grew up underneath the tower of the basilica near the entrance to the atrium. That tower was built, according to the "Liber Pontificalis", by Pope Stephen II (752–757), and reportedly "covered in pieces of gold and silver" (by which is probably meant mosaic decorations in those colors), and provided with three bells, which were a defensive alarm measure. The tower was also decorated with a poetic epigraph, which read as follows, according to De Rossi: