From the beginning of contacts between China and the West, there were on both sides of this uneasy encounter people who – whether only briefly or for the duration of their lives – “crossed over” to the other side. This lecture course is concerned with their history and analysis of the cultural framework, within which they acted. Among cases we shall discuss will be, on the one hand, Chinese commercial intermediaries (compradores) in foreign employ in Chinese ports, converts to Christianity, and intellectuals who became speakers for the West in China. On the other hand, we shall address Western travellers to China since the days of Marco Polo, Orientalists in the late colonial period and thinkers who placed China at the centre of their writing.