When Christopher Columbus landed on the shores of the Americas in 1492, the rulers of the major European powers realised that the world was much larger than they had thought.
In the years following the discovery of the Americas, an era of exploration, trade, imperial expansion and colonisation commenced, which lasted until the middle of the twentieth century.
As a consequence, the global circulation of people, plants, animals and goods increased exponentially, as did the global circulation of disease pathogens. Building and maintaining trade empires and colonial settlement came at a high price for sailors, soldiers, traders, colonial administrators and settlers in the colonies as well as for the populations indigenous to the newly explored lands. The long journeys aboard ship and the sojourns in unexplored territories were often dangerous and damaging to health; colonial settlements generally had very high mortality rates—for this reason Africa was later called ‘the white man’s grave’. Unfortunately, physicians were not familiar with the diseases that had such a devastating effect on colonial settlements. Many physicians believed that the white race did not belong in the tropics and would therefore degenerate and die out within a few generations. It was not until the reception of germ theory in the 1870—1880s that fears about the influence of the tropical climate decreased while attention became focussed on parasites, disease carriers, vectors and microbes present in tropical areas.In this chapter we investigate the diseases that followed imperial exploration, the formation of trading empires and colonial expansion from the sixteenth century onwards. We also focus on the ways in which physicians attempted to assist empire-building by counteracting these diseases. Initially, these physicians focussed on the challenges posed by the tropical climate and investigated ways in which Europeans could acclimatise to the tropics. In the second half of the nineteenth century, they started to focus on identifying disease pathogens and disease vectors, which led to a number of breakthroughs in disease prevention, to the advent of ‘tropical medicine’ as a medical specialty and to the implementation of health policies in colonial settings. After a number of important discoveries, colonial medicine, with some degree of success, focussed on keeping settlers in the colonies healthy and increasing the productivity of the indigenous population. The apparent superiority of Western science, medicine and technology also became an ambiguous marker of the superiority of Western civilisation.