The first building we came across was the Basilica of Constantine. Despite its name, this was not originally a place of worship. In Ancient Roman times, basilicas were large civic buildings. This one was possibly a court house (with lawyers running about). Construction of this basilica began under Maxentius, but after he was defeated by Constantine, the latter completed this basilica and began transforming basilicas everywhere into large places of Christian worship. That's why the word has a religious use today.