It rises on the South-Eastern corner of the intersection of Via San Sebastiano - Via Santa Maria di Constantinopoli, and the Vico San Pietro da Maiella and the outlet of the Via Port'Alba, a narrow alley starting at the medieval gate of Port'Alba.

The church was founded in the second half of the 16th century by a charitable organization that arose in 1548, almost certainly affiliated if not the same as the Order of the Blessed Virgin Mary of Mercy, with the aim of freeing captive Christians who had been captured by Muslim navies and brigands.

In 1706, the church, including the facade with its volutes and obelisk decoration, was rebuilt by Ferdinando Sanfelice.

This church houses the relics of St Alphonsus Maria de' Liguori, gave up his status as a nobleman to follow his vocation to become a priest.

He is depicted at the feet of the Virgin, to whom he was devoted, laying down his sword, and vowing to dedicate to the priesthood.