Sant’Isidoro alle Terme is a small deconsecrated 18th century church in the Via Parigi, near the Aula Ottagona of the Baths of Diocletian. This is in the rione Castro Pretorio, part of the historic rione Monti.
The patron saint was St Isidore the Farmer .
The church was founded on the orders of Pope Benedict XIV, in what was a government granary in part of the ruins of the baths. It served the small population of laypeople starting to settle in the area in the mid 18th century, since all the other local churches belonged to monasteries and convents. However, it was not parochial but was part of the pastoral outreach of the clergy at Santa Maria Maggiore.
The granary had ben established in 1575.
The otherwise rather odd dedication (the saint was a Spanish peasant, the patron of Madrid) seems to have been in order to obtain his intercession as a farmer, that the grain supply for the city was never interrupted. Paradoxically, the granary complex of the Papal government here (the "Granaries of the Popes") was a witness to the destruction of the countryside around Rome as an economic entity. The government had adopted a policy of providing subsidized foodstuffs for the citizens, especially grain for bread, and bought in the requisites for cash from the newly developing commodities markets of Europe. This policy ensured that the local farmers around the city could not compete in growing any worthwhile marketable crops in the long term, and the Campagna turned into the overgrazed sheepwalk that 19th century visitors found so romantic.
The little edifice lost its pastoral justification as soon as local parish churches were built in the 19th century, especially when the adjacent Santa Maria degli Angeli became parochial. It was reported as being out of use and presumably deconsecrated in 1891. The interior was completely gutted in 1940, during archaeological investigations of the site. The roofed void thus created survives, however, and is used as a small exhibition hall.
This was a very small church, on a rectangular plan with a tiny apse. The nave was barrel-vaulted, and the apse had a triumphal arch with Doric pilasters. The capitals of these were continued as a molded cornice running round the nave and apse.
The main altar was the only one, and fitted snugly into the apse with no room to spare. There was an altarpiece showing St Isidore Praying in the Fields by an anonymous early 18th century artist, and this was lit by a flanking pair of vertical rectangular Baroque windows with semi-circular additions at top and bottom. Another horizontal elliptical window was above the altar. The altarpiece had a zig-zag frame, and on the top of this was a triangular pediment broken at the top and with the ends of the break terminating in volutes. The Papal shield of Benedict XIV was inserted into the break, and the pediment was supported by winged putto's heads instead of pilasters. More putti frolicked in a fresco in the conch of the apse.
The simple but pretty little baroque façade survives. It has one storey, and unusually features no columns or
pediments. There are three vertical zones, the central one twice the width of the outer. The outer zones are blank except for a pair of vertical rectangular windows low down, and between each of these and the projecting cornice of the façade is a lightly incised vertical rectangular panel.
The main central zone is brought forward, and unusually the corners thus created are strongly chamfered with an inward curve. The entrance has a doorcase flanked by a pair of thin, stylized doubletted Doric pilasters supporting a raised triangular pediment. Over the lintel and in the tympanum of the pediment are sprays of wheat, a reminder of the granary and its workers that the church originally served. Above this pediment is a horizontal rectangular window with semi-circular extensions at each end, exactly the same style as those in the apse and hence constituting the design motif for the building.
Immediately above this window is a large dedicatory inscription in a recessed panel having an arched top and a molded frame. The original tablet was marble, which has been smashed and several pieces lost; its restoration has used stucco to fill in the gaps. The inscription describes how the pope provided the church for the welfare of the workers in the granary complex.
The crowning cornice of the façade curves over the top of this, where there is a floating archivolt with incurved curlicues at its ends. Above the corncie there is no pediment, another unusual touch, but instead a monumental device in relief that looks like a coat of arms but is, instead, an emblem of a prosperous harvest. A caryatid with a winged putto's head is flanked by curlicues and swinging tassels, and over him is the Papal tiara with crossed keys. To either side is a cornucopia tied by a ribbon, and emptying out heads of wheat.