The Arian baptistery was built in Ravenna in 5-6th centuries by the Emperor Theodoric, a supporter of Arianism. In order to distinguish this from the baptistery of the Orthodox, and gave him such a name – Arian. In 1996, the year he was included in the UNESCO world Cultural Heritage site by UNESCO.

Immediately after the completion of construction at the beginning of the 6th century the space under the dome was decorated with mosaics. In 561, the year when Arianism was forbidden, the baptistery was turned into the chapel of Santa Maria in Cosmedin, built near Orthodox monastery. And from the 18th century and up to 1914, he was in private ownership. By the mid-20th century, the baptistery was surrounded by later additions, however, destroyed during the Second world war.

Architecture Arian baptistery similar to the neonian baptistery: its walls made of unfired bricks, and under the roof you can see the ledge with the toothed ornament. Of course, the main value of the building is the mosaic depicting the scene of Christ's baptism. In these mosaics can notice features of primitivism, which appeared under the influence of the barbarian culture is ready, lords of Ravenna in those days. Interestingly, Christ is here depicted completely naked. Around him are the 12 apostles coming from the crowns to the throne. And among the apostles mosaic painted palm trees.