The kings of Spain forbade foreigners and other 'undesirables' to immigrate to Spanish America. They saw aliens as threatening imperial, religious and mercantile security, and it might therefore be assumed that the Spaniards were xenophobic and intolerant. Dr Nunn's study shows that statutes tell only part of the story. In the years 1700-60 some 3 per cent of the foreign-born in Mexico were non-Spaniards who had entered the colony illegally. Who were...