treasure-trove was then considered as an important branch of the revenue of the sovereign.
What a treasure-trove of music and knowledge that guy has.
British Dictionary definitions for treasure-trove
noun (in Britain)
(law) valuable articles, such as coins, bullion, etc, found hidden in the earth or elsewhere and of unknown ownership. Such articles become the property of the Crown, which compensates the finder if the treasure is declared. In 1996 treasure was defined as any item over 300 years old and containing more than 5% precious metal
anything similarly discovered that is of value
C16: from Anglo-French tresor trové treasure found, from Old French tresortreasure + trover to find