Field studies of black-and-white colobus monkeys (Colobus spp.), African colobines endemic to the forests of equatorial and West Africa, first began in the mid-1950s. Coveted as sources of wild meat and for their often beautiful pelages, most Colobus spp. are today threatened with extinction. Yet, Colobus are also among the most intensively studied colobine monkeys. A wealth of information now exists on this genus, knowledge which has advanced our understanding of many aspects of primate natural history, especially the extraordinary variability in ecology and behaviour that can arise even within a small clade of monkeys with physical adaptations to largely folivorous diets. In this chapter, I review the literature on the habitats, diets, activity patterns, range use patterns, predation threats, social organizations, and sexual behaviour and reproduction of the five monkey species that belong to the genus Colobus (C. angolensis, C. guereza, C. polykomos, C. satanas, and C. vellerosus). I highlight similarities and differences among the different species and populations, and conclude with suggestions for the most exciting and pressing future studies that should be carried out on the natural history of the black-and-white colobus monkeys.