Santa Maria in Vincis was a guild church, now demolished, on Via di Monte Caprino on the west slope of the Campodoglio.
For a lost church that survived into the 20th century, this one is amazingly obscure. Even "Romeartlover", one of the best online sources of information on demolished churches, has overlooked it.
The first mention of the church is in a bull of Antipope Anacletus II (1130-38), and it features again in a bull of Innocent IV in 1252. It was probably built in the 11th century. The Catalogue of Turin lists it as a parish church at the beginning of the 14th century.
The name has been liked with the Latin vinculum which means "something to tie a person up with" or "chain", but in the 13th century the site of the ancient temple of Jupiter Capitolinus was occupied by a garden or smallholding rented from the monastery of Santa Maria in Aracoeli by one Iohannes de Guinizo. The church was early referred to as Santa Maria de Guinizis, which is thought to have been corrupted to in Vincis. In the 17th century it was known as Santa Maria in Monte Caprino.
By the end of the 16th century, the parish had failed and the church was being administered from San Nicola in Carcere. However, it was almost derelict when it was granted to the newly-established guild of soap-makers in 1607 -the Università dei Saponari. Hence, the church was also known as Santa Maria dei Saponari for the rest of its life. The guild thoroughly restored it, and commissioned a main altarpiece showing St John the Evangelist being boiled in oil. This was because in order to make soap they boiled up oil or fat mixed with lye or wood-ashes.
The church was restored at the end of the 19th century by a guild of small shopkeepers, but was doomed by the Fascist determination to destroy all the buildings on the west side of the Capitoline hill in order to make way for their new road to Lido di Ostia (the Via del Mare). It was demolished in about 1929, and the site laid out as gardens.
The demolitions were supervised by Antonio Muñoz. In the process, it was discovered that the fabric contained work of the 12th or 13th century, with two earlier brick arches behind the church showing frescoes of the 9th century depicting saints. These allegedly ended up in the Museum of Rome.
It is difficult now to visualize that the western part of the Capitoline was part of the built-up area.
The present Via di Monte Caprino is a curving garden path, but it used to be a street that ran along about the same alignment (except without the curve). Then it turned a right angle to run steeply down the slope to opposite the Teatro di Marcello. This slope is gone, to be replaced by a set of transverse ramps and stairs by the Casatorre dei Pierleoni. The church was where the top set of stairs and the Via di Monte Caprino meet, and was in the inside angle of the former layout.
The church lacked a separate architectural identity, as it was enclosed in domestic buildings on all sides and above. The plan was a simple rectangle, aligned east to west. There was an entrance at the east end which led into a tiny vestibule, and also on the north side which led to another one.
The latter entrance had a small early Baroque façade. This had two gigantic Ionic pilasters with swagged capitals, supporting a triangular pediment with a broken cornice. The large doorcase with a Baroque molded frame took up more than half the height of the façade, and it was recessed slightly. Above it were two round-headed windows, the latter intruding into the tympanum of the pediment.
As regards the interior, Angeli writing in 1903 has this: "The ceiling, in very bad repair, is in gold and blue and is early 17th century. In the floor are tomb-slabs of Rinaldo Chierico, 1309, also of Buzio di Paolo, of the same period, broken and worn. The altarpiece is an anonymous painting of the 17th century".