The Severan Basilica, 92m long and 40m wide, ran along the northeastern side of the Severan Forum. The basilica, originally a judicial basilica rather than a church, contained two apses at either end, a nave, aisles divided by red-granite columns and possibly a wooden roof. It was started by Septimius Severus and completed by his son Caracalla in AD 216 (read the dedicatory inscription on one of the panels of the nave).
The relative austerity of the main hall stands in marked contrast to the extravagantly sculpted pillars at either end, many of which honour Liber Pater (Dionysius) and Hercules. In the 6th century AD, Justinian converted the basilica into a Christian church, with the altar in the southeastern apse. From the top of the stairs off the northwestern corner are good views of the remainder of the ancient city, although it's not always open.
