San Tommaso in Formis

Situated on the edge of Villa Celimontana and next to the Arch of Dolabella (Porta Caelimontana), a gate in the original Servian Wall, the church is dedicated to St. Thomas the Apostle.

The church is believed to date back to the 10th Century, although the first certain date of its existence is 1209, when Pope Innocent III gave ownership of the church with the attached monastery to the Trinitarian Order whose founder, Saint John of Matha, lived there and made it the Order's headquarters.

In 1532 the first steps towards restoration were undertaken and in 1571 Pope Pius V returned the church, hospital and monastery to the Trinitarians.

The northeast façade of the complex has a Romanesque entrance with a 13th Century mosaic by Lorenzo Cosmati of Christ between two freed slaves.

The founding intention for the Order was the ransom of Christians held captive by non-Christians during the time of the Crusades.