The Madonna del Sudore was first worshipped in Ravenna in very ancient times. According to the legend, a sacred image of the Virgin was housed in the niche of a tavern.

An angry soldier that had lost his money because of gambling, hit the Virgin's face and blood started gushing from the wound.

On 15 June 1675 Andrea Merighi from Ravenna donated a copy of the image to Pietro Monti from Castel del Rio.

The original painting is on wood while Castel del Rio's copy is on canvas.

The Madonna del Sudore's worship became widespread among Castel del Rio's inhabitants so that it was decided to built an oratory in her honour.

In 1684 a procession was held to celebrate the laying of the foundation-stone. The oratory was rapidly built also thanks to people's donations.

The first Mass was served in the new church only three years later, in 1687.

The oratory was erected exactly on the ruins of the Church of Saint Ambrose (Sant'Ambrogio) dating back to the early Middle Age and housing the Alidosi's tombs.
Inside, the church is decorated in Baroque style. A beautiful wooden niche houses the sacred image of the Madonna.

The oratory was renovated in 1874 and 1915. In 1924-25 the sacristy was restored and an elegant façade was added.

In the façade are two memorial tablets with the 74 names of Castel del Rio's inhabitants who died during the First World War.

Lastly, in 1930-31 an iron fence was added.