There is a related item on the church (photo) mentioned in the text below. What follows (without further comment, other than that I found it very interesting) is the English-language text of an historical display on the premises of the main Bank of Naples in the city.

"Aiding the congregation of the Santa Maria della Redenzione dei Captivi to free those of the Kingdom captured and enslaved by the Saracens.

"For many centuries, Mediterranean peoples were troubled by piracy. The captives that were taken during these pirate raids were sent as slaves mainly to Tunis, Algiers and Tripoli. The Normans, Swabians, Angevins and Aragonese tried to set up coastal defenses, but it proved very difficult to control two-thousand miles of coastline from San Benedetto del Tronto to Gaeta. Even the Spanish and Austrian viceroys who ruled for approximately 250 years were not able to prevent pirate raids. In fact, there was a recrudesence because these two European states had never declared war against the Muslims. It was only following the peace treaty of 1740 between the Kingdom of Naples and the Ottoman Empire that a renewal of trade was attempted. However, pirates continued to operate undisturbed in the western Mediterranean up until the early 19th century.

"Among its philanthropic works, the Banco e Monte della Pietà contributed to the realease of slaves. Each year, the institution would set aside part of its profits which it would entrust to the Confraternity of Santa Maria del Gesù della Redenzione dei Cattivi di Napoli, the first Italian lay institution, formed in 1548. The Confraternity would send its represenatives--also called "Redeemers"--to African countries, mainly to Algiers, Tunisia, and to the island of Tabarca. As described in the institution's statutes, a redeemer was required to be a "conscientious and upright person," so that his task could be carried out "without personal designs, self-interest or attachment". Specially chartered vessels were used for these voyages of Redemption as they were known. On the outbound voyage, the vessels carried gifts for the various Rais, as well as an appropriate amount of money to pay the required ransom to release the slaves.

"The slaves were mostly paupers that had been captured in Sicily, Puglia, along the Amalfi coast, and on [the islands of] Ischia and Procida. Without the contribution of the banking institution and other pious organisations, these slaves would never have been able to regain their freedom. After receiving information about the actual condition of the slaves that were to be freed, the governors of the Confratetrnity set about drawing up special documents (albarani) stating the amount of money to be paid for the slave mentioned in the document. This document served as a guarantee for the release, but payment was made later in Naples after verifying that the slave had actually been released. The average cost of a slave was 100 ducats, but this amount was dependent upon many factors: age, sex, physical health, ability to work and social class. Between the years 1601 and 1615, the accounts held by the Confraternity at Neapolitan banks showed transactions totalling approximately 100,000 ducats, which indiates the large number of Christians that had fallen in to the hands of the infidels."