There have been few scientists who have had a greater impact on the history of vector biology than Sir Patrick Manson (1844-1922). By demonstrating that mosquitoes became infected with microfilariae in the process of taking a blood meal, he became the first to prove an association between insects and pathogens causing human and animal diseases. He also contributed substantially to the discovery of mosquito transmission of malaria parasites and was a principal force behind the founding of the London School of Tropical Medicine and the Royal Society of Tropical Medicine and Hygiene. Manson's career is reviewed in historical context as well as in relation to modern concepts of vector biology.