Originally known as the Basilica of Saint Peter Apostle, it was built at the bottom of the hill of Montedoro, where the old medieval site of the city was situated.

The Basilica has a characteristic cloister that incorporates an African Museum (administrated by missionary friars) and the Library of the Capuchins, which has a collection of over 15,000 volumes.

In the 11th and 12th centuries, the church of St. Peter of Eboli was part of three local feudal domains created by the Roman Catholic Prelates appointed by the Lombards.

[6] In 1743, Benedict XIV assigned the abbey of Saint Peter to the College of Chinese, directed by Matteo Ripa.

[7] The nomenclature Basilica of St. Peter Alli Marmi was assigned in 1930, due to the significant presence of marble within the complex.

[2] The Convent of St. Peter Alli Marmi is a rectangular building with three different levels and features an internal cloister as a central component.

[5][8] The main facade is elevated compared to the current road level and encompasses a two-storey central body with an arched portal.

The ground floor is characterized by a covered porch with groin vaults, supported by round arches with stone archivolts, upheld by square pillars.

The entrance, originally located on the wall opposite the apse, now opens onto the right nave and is characterized by a simple stone portal adorned with the coat of arms of the House of Carafa.

[8] The first documented mention dates back to 1090, where it is referred to as "sancti petri apostoli quod situm est foris et castelum evuli."

The crypt has a cross-vaulted ceiling supported by marble columns and is rectangular in shape with three apses corresponding to those of the upper Basilica.

[8][22] Saint Berniero was born in Northern Spain, in the city of El Burgo de Osma, the ancient Uxameburg.

Berniero belonged to a wealthy noble family, but since he was a child, he pursued a life of austerity, rejecting vanity and futility.

[23] When Berniero landed in Italy, he first visited Saint Peter's grave in Rome, then settled in the city of Eboli.

When he died, another miracle happened: frozen oil melted and kept on falling from the jars situated on the oil-press in the Benedictines' monastery.

On the left side of the apse is a statue of St. Fidelis of Sigmaringen made out of wood, created by the sculptor Giacometti Colombo in 1690.