Der heilige Markus predigt in Alexandria

This enormous canvas, wider than most rooms, shows Saint Mark preaching in Alexandria, but the Alexandria Gentile Bellini paints is stitched together from things he had actually seen. In the 1470s Venice had sent him to Istanbul to work for the Ottoman sultan, and he came back with a memory full of minarets, turbans and camels, which he pours into this imagined Egypt behind a very Venetian-looking square. He began the picture in 1504 for one of Venice's great civic brotherhoods. He did not finish it. When Gentile died in 1507 he left instructions in his will that his more famous younger brother, Giovanni Bellini, should complete the work, and Giovanni did, changing some parts as he went. So two brothers, one just gone, share a single vast surface.