The Feast of the Transfiguration has been celebrated in the Eastern church since at least the 6th century and it is one of the Twelve Great Feasts of Eastern Orthodoxy, and so is widely depicted, for example on most Russian Orthodox iconostases. In the Western church the feast is less important, and was not celebrated universally, or on a consistent date, until 1475, supposedly influenced by the arrival in Rome on August 6, 1456 of the important news of the breaking of the Ottoman Siege of Belgrade, which helped it to be promoted to a universal feast, but of the second grade. Most notable Western depictions come from the next fifty years after 1475, reaching a peak in Italian painting in the 1510s.