There’s been a church on this site – just five minutes’ walk from the Colosseum – since the 5th Century when it was built to house relics from chains (vincoli) said to have held St Peter in Jerusalem. They came to Rome via the Empress Eudoxia (whose name is still remembered in the street outside), after whom the original Basilica Eudoxiana was named. She gifted them to Pope Leo I. The legend goes that when he compared them with the chains that had apparently held St Peter in Rome’s Mamertine Prison, the two miraculously fused together.
The façade we see today shows no sign of those ancient origins, as the site has seen many refurbishments, the last major one having taken place in the early years of the 15th Century by Pope Julius II, who commissioned Michelangelo to build his famous Moses as a tomb.
The chains are now held behind the high altar.
However most people seemed to be there to see Michelangelo’s Moses, originally destined to be the tomb of Pope Julius II, and completed in 1515.
Other treasures include the mosaic of St Sebastian, dating from the 7th Century.
Definitely worth a short detour if you’re in the area near the Colosseum.