In 307 AD, Emperor Maxentius rededicated the temple of Jupiter Stator into the Temple of Romulus as a memorial to the death of his son, Valerius Romulus. In 527, Pope Felix IV had the circular building connected to a library (Bibliotheca Pacis) in the Forum of Peace (Forum of Vespasian). He then converted them into the Basilica of Santi Cosma e Damiano. The namesakes, Saints Cosmas and Damian, were twin brothers from Greece. They donated their skills as doctors until martyred in 287 for their Christian faith. This entrance from the Roman Forum was opened in 1879.
