History is written in blood, however elegant the cover. Nowhere is this more apparent than in the collapse in 1521 of the Aztec Empire, a culture that presented Europe with a vision of such otherness that it could only be destroyed. In 2002, the Royal Academy of Arts tried to persuade us to look beyond the grisly tales of human sacrifice to a more nuanced portrait of a people steeped in gory rituals that we, soaked in the serial-killer television porn of the 21st century, might strangely understand.