Set back from the busy square in front of it, this modest church can boast of a long heritage. The founder, St. Eusebius, is recorded as being a priest of the Roman church in the fourth century.
Holding the orthodox doctrine regarding the divinity of Christ in the tumultuous period after Nicaea I, he was condemned to death by starvation in 357 after defending St. Athanasius before the Emperor Constans. This sentence is believed to have been inflicted in his own house, which later became a titulus under his name. This tradition was strengthened by the discovery beneath the current edifice of Roman ruins dating back to the second century. The first record of the titulus dates from 474, although archeological remains hint at an original construction date of the church around the turn of the fifth century.
This first church was restored around 750 before being rebuilt later that century. Another reconstruction, under Pope Gregory IX, was completed in 1238 and commemorated in a plaque still to be found in the porch. A campanile was added around this time as well. The old church was extensively renovated and redecorated from 1711 to 1750, giving us, with a few later changes, the church as it stands today.
Overlooking the steps leading up to the church is a statue of Our Lady, given by parishioners on the occasion of the Marian Year of 1954. Behind this, set into the back wall of the porch, are plaques commemorating various occurrences here through the centuries, including one marking the renovation that took place under Pope Gregory IX (1241).
Going into the church, your eye is drawn to the ceiling image of St. Eusebious in glory holding a tablet on which is inscribed the Greek phrase meaning "consubstantial with the Father," [should sound familiar, yes? The creed...] the doctrine for which he suffered. Under the high altar in this church are the relics of St. Eusebious and two other saints, St. Orosius and St. Paulinus. An image of the Blessed Virgin and Christ Child is kept over the altar. To the right is an altar dedicated to St. Benedict, over which is a painting of the saint consoling the residents of Cassino after the Lombards attacked the town.
In this church is an altar dedicated to St. Celestine - the only Pope (prior to Benedict XVI) to resign the Office. Celestine was a monk who, in 1294 was elected to the See of Peter after two years of infighting amongst the cardinals during the conclave. But less than one year into his reign, he resigned, believing the demands of the office beyond his abilities (that, too, should sound familiar). An order founded by him once cared for this church, which is why he is commemorated here. He is shown giving away the instruments of his office, being a true example of one who puts his discernment of the Lords' will ahead of his own desires.