The expansion of the collection was essentially achieved during the next decade. Three major coin cabinets were acquired in their entirety. The first consisted of the Byzantine series in Grierson’s private collection of medieval coins (530 coins including 120 in gold). The second was an immense collection of some 5,000 coins assembled mainly in the Balkans by the Italian diplomat and scholar, Tommaso Bertelè (1892–1971), acquired in two groups in 1956 and 1960. It contained a unique series of Paleologan coins, virtually unrepresented in the public collections in London, Paris, and St. Petersburg. The third was that of the Austrian collector Leo Schindler (1885–1957); his 2,500 coins were particularly rich in specimens of the 6th and 7th centuries, with exceptionally good coverage of dates, mints, and officinae. In addition many individual coins, and groups of coins, were acquired during this period from dealers and at coin auctions, mainly on the European mainland. By 1963 the collection had assumed approximately its present size (ca. 12,000 coins). The funds for virtually the whole of this extraordinary expansion were provided by Mr. and Mrs. Bliss.