On the southern side of Piazza Bellini, this luminously beautiful 12th-century church was endowed by King Roger's Syrian emir, George of Antioch, and was originally planned as a mosque. Delicate Fatimid pillars support a domed cupola depicting Christ enthroned amid his archangels. The interior is best appreciated in the morning, when sunlight illuminates the magnificent Byzantine mosaics.
In 1433, the church was given over to an aesthetically challenged order of Benedictine nuns – founded by Eloisa Martorana, hence its nickname – who tore down the Norman apse, reworked the exterior in a fussy baroque fashion and demolished most of the stunning mosaics executed by Greek artisans, replacing them with the gaudy baroque ornamentation of their own frescoed chapel. The few remaining original mosaics include two magnificent portraits, one representing George of Antioch, crouched behind a shield at the feet of the Virgin Mary, and one of Roger II receiving his crown from Christ (the only portrait of him to survive in Sicily).
Today the church is overseen by the Eparchy of Piana degli Albanesi of the Italo-Albanian Catholic Church, who celebrate mass according to the traditional Greek Rite.