The history of humanity as told through one hundred objects from the British Museum in London. This week Neil MacGregor is looking at the co-existence of faiths - peaceful or otherwise - across the globe around 400 years ago. Today he is with a document that shows what happened after Catholic Spain's conquest of Mexico - it's an old map, or codex, that was made at the height of the Spanish church building boom in Mexico. Neil uses the object to consider the nature of the Spanish conquest and to explore what happened when Catholic beliefs were assimilated alongside older pagan beliefs. The historian Samuel Edgerton offers an interpretation of the map that shows churches alongside older temples, and the Mexican born historian Fernando Cervantes considers the ongoing legacy of the great Christian conversion.