The High Altar was financed, as was the floor, by the Prince of San Nicandro, tutor to Ferdinand IV of Bourbon, King of Naples and Sicily and patron to many artists.
It is of engraved marble and encrusted with precious stones which thieves have often attempted to steal. It was made in Naples in 1719 by the master marble cutter Agostino Chirola, to a design by Angelo Barletta.
On either side of the altar are two magnificent angels each carved from a single piece of marble. They are said to be Michelangelesque because of their luminosity and transparency.