Rubisco is possibly the most important enzyme on Earth, certainly in terms of amount. This review describes the initial reports of ribulose 1,5-bisphosphate carboxylating activity. Discoveries of core concepts are described including its quaternary structure, the requirement for post-translational modification, and its role as an oxygenase as well as carboxylase. Finally, the requirement for numerous chaperonins for assembly of rubisco in plants is described.