But what you see in the Aztecs show is taken from the top of this heap, from the ruling class, the crème de la crème. These objects - statues, masks, stone carvings, printing blocks, drinking vessels, enameled plates, images of gods and devils, golden ornaments, brightly coloured featherwork, richly decorated skulls, illuminated manuscript-books known as codices - are what the Aztec aristocracy bequeathed the world, if rather more suddenly than they imagined. You also get objects from a fusion-period after the Spanish conquest, when Aztec craftspeople switched to the new religion and for a while served the Spanish monks as they had served their old masters. After that, the process of inter-breeding and the wholesale adoption of Spanish practices put the lid on the whole era. The Mexicans of today, though they are keenly aware of their Aztec forbears and fiercely independent, have a shared past: much European blood and history in the mix.

The RA's exhibitions secretary, Norman Rosenthal, says: "What really, completely amazed me, the first time I went to Mexico, was the speed with which Western Renaissance culture took over. It's amazing how, in a very short space of time, Christian classical sculpture put its mark on that part of the world, with great sophistication. Within about 20 or 30 years, you'd think you were in Renaissance Italy. It was the equivalent of building skyscrapers, or moon colonies."