Reputed as one of the most beautiful Early Christian compounds of Antiquity, Piazza Capitolo includes the basilica, the baptistery, the südhalle and the campanile.
The first Christian basilica was erected in Aquileia few years after the Edict of Milan of 313 AD, whereby Emperor Constantine granted freedom of worship to Christians. Four more churches were built on top of the first one during the following centuries.
Today's church is custodian to an authentic work of art: the largest Early Christian mosaic of the Western world (750 m²). The basilica was built on the initiative of bishop Theodore in the early 4th century. The mosaics of the southern hall tell three episodes of the story of Jonah: the sea monster swallowing the prophet who had refused to go and preach in Nineveh; Jonah thrown up onto the beach before starting his mission; Jonah resting in the shade of a trellis after converting the city. The whole story is an allegory of the death and resurrection of Jesus Christ and, in broader terms, of the afterlife reserved to the baptised. The mosaics of the Northern hall bear a more complicated symbolism. What is more striking here is the intensity of colours and the perfection of the scenes depicted on the floor, including the fight between a cockerel and a tortoise symbolizing the victory of Orthodox faith over heresy.