(Updated March 2023) The loss of Cyprus to the Turks in 1571 provoked action by the Christian league under Don Juan of Austria, the illegitimate half-brother of Philip II of Spain. A fleet of over 200 galleys proceeded to the Gulf of Lepanto (now Naupactos) where they met the Turkish fleet on 7 October 1571. The galleys were mainly Venetian and Spanish but included squadrons from the Papal States and Genoa. Although the Christians were outnumbered on the flanks they triumphed in the centre and the Turks were eventually defeated.

The battle is memorable as the last great galley action and for the large number of people who were killed; about 25,000 Turks and 8000 Christians. The painting is an imaginative interpretation of it, with a high horizon and a sea littered with galleys locked in combat. A rocky coast is implied on the left, and land on the right, including the entrance to Lepanto. Smoke around the galleys indicates the ferocity of the battle at close quarters and inscriptions in Italian, some now fragmentary, identify a number of the participants. In the left foreground is the galley of Gian' Andrea Doria (IL.GIO.ANDREA.DORIA), the commander of the Genoese squadron, together with the right wing of the Christian fleet. Immediately to his left with a large white cross on her stern awning is the flagship of the Genoese Negrone family (LA CAPITANIA DENEGRNI). The central galley these two are confronting is marked 'TRIPOLI' and may, from a fragmentary inscription toward the bow, be intended as the Barbary galliot of Piali Murad. Immediately behind that, with a striped awning decorated with crescents, a galley marked 'CAVRALICO' is that of the corsair Caur Ali, with another corsair, Kara Hodja (CARACOZ), two beyond.

Among the mass of galleys and galleasses behind are standards displaying the Lion of Venice, the red St George's cross of Genoa, and the gold and silver standards of the Papal States. Don Juan's flagship is in the middle distance, left of centre, with its standard of Christ on the Cross and flying the Habsburg double-headed eagle, which also appears elsewhere. She is assisting a Venetian galley in attacking the flagship of Ali Pasha, the Turkish commander-in-chief, with the standard bearing the three crescents. Just to their right is the flagship of Marc'Antonio Colonna, who commanded the division from the Papal States. There are two galleasses on the right of the picture: their design was an attempt to combine a broadside of guns with oars.

In the right foreground the galleys making off are those of the Turkish left wing, the closest bearing a long inscription identifying the Christian renegade, Uluch-Ali; OCHIALLRE.DALGIERIFUGE.DALLABATTA.GLIA. (Ochiali, King of Algiers flies from the battle). The galley of Murat Reis flies a horizontal three-stripe ensign with a single crescent on the central bar directly above the stern of Uluch-Ali's. There is a woman in the stern of the Christian galley two up from the Negrone flagship. She holds the head of a Turk in her right hand and the sword with which she removed it in her left.

There is a compositionally similar painting by a different hand, and more heavily inscribed, in the Museo Correr, Venice, and both oils relate to Venetian prints of the same viewpoint and composition: one is by Martin Rota, dated 1572 (see PAF4402) but the prime source may be a large four-block woodcut by Cristoforo Guerra (Christof Krieger of Nuremburg), who settled in Venice about 1550 and died there in 1589/90. This was published there by Domenico Louisa (or Lovisa). The Museo Correr has an impression the lower left corner section only, with the imprint cartouche centred on Andrea Doria's galley, so blocking full view of it. A full copy is in the Bibliotheque Nationale, Paris, and another reported to be in the Uffizi, Florence. The Guerra image is heavily inscribed and probably ultimate source of this one and the rather fewer identifications on it.

The previous history of the NMM painting is not known, except that it was purchased in 1945 from Spink's, having previously been obtained by a London dealer known for finding things from English country house collections. The prominence of the Negrone galley may indicate that family as original owners. The otherwise unknown artist has signed it 'HLETTER' (H and L joined) immediately after the inscription identifying Uluch-Ali. In 1960, Cecil Gould of the National Gallery, London, suggested 'Austro-Flemish school' as a possible association but no further information has yet been found. The lower half of the canvas is re-used, transparency of the over-painting through age showing the underlying image of the upper half of an heraldic cartouche, with a fragmentary inscription and two male supporters, one bearing a trident and the other a sword.