The 12,000 coins in the Dumbarton Oaks Collection and the Whittemore Collection at the Fogg Art Museum form one of the greatest specialized collections of Byzantine coins in the world. The catalogue, edited by Alfred R. Bellinger and Philip Grierson, publishes the majority of these coins, dating between 491 and 1453, in five volumes.The third volume in this catalogue is in two parts. Part I examines Leo III to Michael III (717–867) and Part II covers the period between Basil I and Nicephorus III (867–1081). Continuing the practice established in volume two, an extensive general introduction treats the historical background, the monetary system, mints and mint activity, and types and inscriptions, while the introduction to each reign covers chronology, main features of the coinage, and types issued by mint.