Robert Vaughan has made a number of seminal contributions to the additive theory of numbers, including his demonstration of the asymptotic formula for the eight cubes problem, the proof of which had eluded many eminent predecessors. He discovered an important identity — now known as Vaughan’s identity — that has been very influential in recent number theory, and which played a substantial role in the recent elucidation of the Kummer conjecture by David Heath-Brown and Samuel Patterson. Robert is also well known for his fundamental work in multiplicative number theory done either alone or in collaboration with Hugh Montgomery, including a recent proof of a long-standing conjecture due to Erdos concerning the distribution of numbers relatively prime to a given large number, n. He was awarded the Junior Berwick Prize of the London Mathematical Society in 1979.