The Santa Maria cathedral, with is thousand year history, is without a doubt the most important place of worship of the Ivrea city, built in a relevant position, where it is hypothesised the roman acropolis was. The most antique part of the crypt, of carolingian influence, it is characterised by a ring shape, with typical cross-shaped vaults supported by thin columns and half conical capitals. The most recent part of the crypt (XII and XIII century) is distinguished thanks to its capitals with vegetation or zoomorphic decorations and wall operations.
There are also frescos from different eras and among the subjects represented you find two Warrior Saints, San Gaudenzio, an Annunciation and a work attributed to Giacomino da Ivrea representing the Madonna with Child among saints Cristoforo and Antonio Abate During the excavation campaign in the Nineties, the great round pillars from the Roman church were brought back to the light. The early Christian building, probably built in the IV century, was rebuilt around the year One-thousand, upon request of the Bishop Warmondo, according to a layout that is typical for three nave Ottonian buildings with counterposed apses, where only the western one remains. Between the 15th and the 16th century a new sacristy was built, containing paintings by Defendente Ferrari. The current look of the inside of the cathedral is a result of interventions mid 18th century, such as building the Santissimo Sacramento and Crocifisso chapel and the Sacrament Chapel, built in 1761 in honor of San Savino, patron saint of Ivrea. The Crocifisso Chapel was desired by the bishop OttavioPochettini, who contacted the architect Giuseppe Martinez in 1786 in order to obtain a homogenous style for the interiors and particular the nave. The last important transformation of the cathedral was the expansion towards the East of the span and demolition of the 16th century facade.