The Dumbarton Oaks coin collection is known worldwide for its extensive and comprehensive six-volume catalogue. Many of these volumes are still the primary reference for their respective periods. The catalogue has been instrumental in building the reputation of the institution. The Dumbarton Oaks coin catalogue (hereafter DOC) includes both the Whittemore collection (2,887 coins) and the Dumbarton Oaks collection (ca. 12,000 coins). Thomas Whittemore (1871–1950) left behind no information on his sources, but he must have assembled his collection mainly on the Istanbul market during his work there. First he was involved in the relief of Russian refugees after the First World War, and later, thanks to the support of Kemal Ataturk, he worked on the restoration of the Hagia Sophia mosaics from 1936 until his death, and on the Chora monastery (Kariye Çami).