The Cathedral of Santa Maria Assunta (Cattedrale di Santa Maria Assunta) is a basilica church on the island of Torcello, Venice, northern Italy. It is a notable example of Venetian-Byzantine architecture, one of the most ancient religious edifices in the Veneto, and containing the earliest mosaics in the area of Venice.According to an ancient inscription, it was founded by the exarch Isaac of Ravenna in 639, when Torcello was still a rival to the young nearby settlement at Venice. The original church is believed to have had a nave with one aisle on each side and a single apse on the eastern wall of the cathedral. It’s difficult to tell what the original church was like because very little of it survived the subsequent renovations. Much of the plan of the original church survives as its present form is very similar to the original but the only physical parts that survive are the central apse wall and part of the baptistery that survives as part of the façade of the current church.