It was built in 1630, when the terrible plague killed nearly a third of the population, and the Senate took a solemn oath to thank the Virgin Mary for protecting the city and saving the power of Venice. Adjacent to the customs house, the new church was designed by the young architect Baldassarre Longhena, with an innovative baroque-style design, the centralized layout and the beautiful dome. The church "made in the form of a round monument that has never been seen, nor ever before invented", as the architect said, was completed only after he died in 1687.