It is dedicated to St. Alphonsus Liguori, the founder of the Congregation of the Most Holy Redeemer (Redemptorists), who built and staff the church.

The interior decorations, rich with marble, from the end of the nineteenth century, are by the Bavarian painter and Redemptorist Max Schmalzl (1850-1930).

The apse is crowned by a mosaic, put in place in 1964, depicting the Redeemer enthroned between the Virgin Mary and Saint Joseph.

This icon was claimed to have been stolen from Keras Kardiotissas Monastery[2] in 1498 and given to the Redemptorists by Pope Pius IX in 1866.

Saint John XXIII named St. Alphonsus a Cardinal Titular Church on 30 December 1960 as SS.