Sant'Eusebio is a titular church devoted to Saint Eusebius of Rome, a 4th-century martyr. The church is first mentioned in 474, by an inscription in the catacombs of Saints Marcellino e Pietro. It was consecrated by Pope Gregory IX, after the restoration of 1238. The Romanesque style, dating back to this restoration, survived to the restorations of the 17th, 18th, and 20th centuries.
The interior is separated into a nave with two flanking aisles. The present design dates to 1600 work by Onorio Longhi, who restored the presbytery, main altar, and choir. The ceiling fresco is a neoclassical masterpiece of Anton Raphael Mengs depicting the Glory of Sant'Eusebio (1757). Other paintings in the church are attributed to Giuseppe Passeri (central nave window), Andreas Ruthart (choir), Baldassarre Croce (Jesus, Mary, and Saints near the main altar), Cesare Rossetti (Crucifix at the main altar facing choir), Pompeo Batoni (Madonna and Bambino near main altar) and Francesco Solimena.
The main altar has custody of the relics of St Eusebius of Rome, who is supposed to have commissioned and financed construction of the church in the 4th century. The church is supposedly built on the site of his house.References:
The Basilica of Santa Maria in Trastevere is one of the oldest churches of Rome. The basic floor plan and wall structure of the church date back to the 340s, and much of the structure to 1140-43. The first sanctuary was built in 221 and 227 by Pope Callixtus I and later completed by Pope Julius I.
The inscription on the episcopal throne states that this is the first church in Rome dedicated to Mary, mother of Jesus, although some claim that privilege belongs to the Basilica di Santa Maria Maggiore. A Christian house-church was founded here about 220 by Pope Saint Callixtus I (217-222) on the site of the Taberna meritoria, a refuge for retired soldiers. The area was made available for Christian use by Emperor Alexander Severus when he settled a dispute between the Christians and tavern-keepers.
The church underwent two restorations in the fifth and eighth centuries and in 1140-43 it was re-erected on its old foundations under Pope Innocent II.