It is assumed that the foundation of the church dates back to the 7th century when the refugees began to leave the mainland at the end of the Barbaric invasions and moved to the island of glass. The place of worship was originally named after Santa Maria, who was later joined by the Saint Donatus martyr, bishop of Evorea, in 1125, when the remains of the latter arrived in Venetian territory after the conquest of Cephalonia by the navy, captained by the Doge Domenico Michiel.
Like most Venetian buildings, the church also underwent renovations in the 9th century before being rebuilt in the 12th century. The exquisite paving dates back to this period (around 1140) and was used as an example for other similar projects (for example, the Abbey of Pomposa). Even non-experts can easily appreciate the beauty of its mosaics made of marble and colorful glass pieces.
The sacred place has a basilica plan and is composed of two side aisles divided from the nave by five Greek marble columns with Venetian-Byzantine capitals. The apse, facing East, overlooks the northern lagoon of Venice while the Early Chrisitan facade faces West. Precisely the apse, which is the first structural element to be seen by those coming from the fondamenta, is distinguished by an internal hexagonal plan and a false exterior portico, with niches and twin columns in two orders. The façade, on the other hand, follows the typical rules that are also applied to the Basilica of Ravenna and appears to be of lesser importance than the apse, also because you have to walk around an entire side of the church to see it.
As for the interior, the painted panel deserves special mention as being one of the oldest in the Venetian tradition and the magnificent mosaic depicting the Madonna praying. Inside are also works by Bartoleomeo Letterini such as San Lorenzo Giustiniani to whom the Child Jesus appears while celebrating Mass on Christmas night, of Marco Vecellio with Descent in Holy Spirit, of Nicolò di Pietro with Four evangelists, and of Lazzaro Bastiani with Saint John the Baptist and Donatus present Giovanni Degli Angeli to the Madonna and Child. There is also an altarpiece which presents six Saints with the Assumption in the center and under other twelve Saints with Cristo Passo at the center, by a disciple of Paolo Veneziano.
The bell tower maintains a square shape and is divided into three sections with a belfry at the head composed of three-light windows and a crowning of arches. Located in the Campo San Donato and slightly detached from the church, the bell tower is adjacent to a grandiose Monumento ai Caduti by Napoleone Martinuzzi (dated 1927).