The Republic of Cyprus (RoC) became the 12th member to join the Commonwealth on 13.3.1961. Whereas nowadays the RoC seems like a perfect fit, admitting a small state was controversial when it applied for membership. The entry of the RoC as a member was a landmark in the history of the Commonwealth, as it was the first small state to join. Furthermore, although a number of Commonwealth members had adopted republican constitutions in the years following their independence, the RoC was the first member to join the Commonwealth as a republic. Today, the Commonwealth is very different. It comprises 56 members, out of which 33 are classified as small states. The majority of members are republics, whereas some members have no links to the former British Empire. Since admission the RoC has established itself as an active and enthusiastic member. However, research output regarding RoC-Commonwealth relations has so far been limited. The objective of this monograph is to offer a comprehensive account of the relationship between the Commonwealth and the RoC. This has not been previously attempted, and I therefore hope that it will fill a vacuum, and prove useful to Commonwealth researchers and practitioners.