The toponym "polesine"' reminds us that the convent stood on an island situated downstream of the point where the two principal branches of the early medieval Po (the Po di Volano and the Po di Primaro) used to meet. The Benedictine nuns, led by Beatrice d'Este, took possession of the island in 1257 after purchasing it from the Augustinian friars for the sum of 1000 old ferrarini and the necessary conversion work began immediately. In 1287 the work was probably still in progress.
After this first phase, which marked the enlargement of the convent, archaeological investigation has made it possible to document a series of additions and conversions, also corroborated by a document drawn up in November 1467, which concerned a part of the area previously occupied by the 14th century structure.
The new building, which now forms the southern side of the second cloister, marked a significant increase in the size of the complex. The remaining part of the previous structure was then used as a craft workshop.
The convent enjoyed enormous importance during the Renaissance and its illustrious guests include the Popes John XXII (1414) and Pius II (1459). In 1438 Pope Eugenius IV stayed there on the occasion of the Ecumenical Council; according to a description taken from the acts of this assembly, the convent had vast hospitality areas in which it could house illustrious guests.
Right from its foundation, as a matter of fact, the convent was the place the city's most aristocratic girls took their vows: among the sixty nuns in the convent in 1466 there was also Margherita, Borso d'Este's sister.
Proof of the wealth and importance of the convent is provided by the types of materials found in the course of the dig: the quality of the objects tends to suggest high society more than a religious community. Together with the characteristic monastic scratch-decorated earthenware, adorned with various types of religious symbols, a great number of remarkably fine objects have also come to light, including imported Spanish earthenware and Venetian glass.
In particular, a dig carried out in a walled subterranean dump has produced over a hundred objects in an excellent state of preservation: goblets, plates, bowls, jugs and fruitstands that in some cases make up complete table services.
The decorative work includes monastic subjects but also a great number of not specifically religious subjects such as figures of animals, emblems, geometrical patterns, profiles of women and some deeds of the Este family. Many of these objects have the name of the nun who owned them scratched under the stand.
There are also numerous bottles and glasses in the form of truncated cones and stamp-decorated with droplets, lozenges and parallel lines. Along with these everyday objects there is also an outstandingly fine large cup or fruitstand in blue glass decorated with ribbing. The object, produced on Murano using a complex technique, probably on commission, is comparable to similar objects kept in the Glass Museum in Murano and the Victoria and Albert Museum in London.
Starting from midway through the 16th century, the western side of the courtyard area was used as a refuse dump. This area has given up monochrome, blue-green and yellow earthenware decorated with cyphers, symbols and figures of nuns, often inserted within wreaths of floral or geometric patterns.
This so-called conventuale or convent-style pottery was produced exclusively for the great religious communities and even came to form personal services comprising jug, plate, soup plate, and bowl. The strata of these dumps dating from around the mid 1500s contained predominantly items in majolica ware in the compendiario style: white enamel with very fine ornamentation in sky blue, yellow and brown, which was the height of fashion in the mid 16th century.
Among other exceptionally beautiful and historically valuable items of glassware there is a drinking glass with stem and cup stamp-decorated in a kind of opaque white glass, known as milk-scab, with streaks of blue, red and gold; this last effect was obtained with a gold-flecked glass called avventurina, a name that testifies to the casual nature of its discovery.
The formularies kept on Murano that illustrate the composition of the various types of glass date this discovery at the early 16th century: the dig at Sant'Antonio has made it possible to backdate this discovery by about fifty years. In this way archaeological research has enabled us to open up a window of about three centuries on the life of the convent, allowing us to reconstruct the standard of living enjoyed by the nuns therein, and restoring to us their names, their crockery and personal objects.