Gentile Bellini, 'Cardinal Bessarion with the Bessarion Reliquary', about 1472-3

This intriguing picture is as much a portrait of an object as the three men surrounding it. The figure in black is the Greek cleric John Bessarion, who reached the rank of archbishop in the Greek Orthodox Church. His attempts to unite with the Catholic Church brought him favour in Italy, where the pope made him a cardinal in 1439.

Bessarion became a permanent resident in Venice in 1453, after the fall of Constantinople, the capital of the Byzantine Empire, to the Islamic Ottoman Empire. He joined the Scuola della Carità, a religious confraternity, ten years later; the two men in white robes here are high-ranking members of that confraternity. The one to the right holds an instrument for self-flagellation, a practice that involves whipping your own flesh in order to purify your spirit.

The painting was made as a decorated door panel, and holes for the handles – now filled in – are still visible on the right hand side. It was part of a tabernacle which contained the reliquary before which the three men in the painting kneel in adoration. Reliquaries were made to hold relics – in this case two fragments thought to come from the Cross that Christ was crucified on, as well as two scraps of fabric which supposedly came from his garments. These were contained in compartments above and below the upper arms of the golden crucifix in the centre of the reliquary. Bellini’s picture protected the reliquary, reminding those who passed it of its presence, and commemorated Bessarion’s generosity.

Bessarion donated the reliquary to the confraternity in the hope that it would inspire western Christians to help Greek Christians after the fall of Constantinople. Appropriately, it was a mix of Byzantine and Italian elements. Part of the paint surface are quite damaged but we can see the gold crucifix at its centre, which originally belonged to the Byzantine princess Irene Paleologina. It was later attached to a wooden box faced with blue and gold enamel, though Gentile has simplified the design. The two figures contained within vertical rectangles on either side of the Cross show the emperor Constantine and his mother Helena. Constantine was the founder of Byzantium, having converted to Christianity in 312 AD; Helena discovered Christ’s Cross.

Many of Gentile’s pictures celebrate the links between Byzantium and Venice but none quite as explicitly as this one. Less than ten years later Gentile was in Istanbul painting the portrait of the Ottoman ruler, Mehmet II – a sign of Venice’s resilience, commercial attitude and the role of art in diplomacy.