There is also another very antient hereditary duty belonging to the crown, called the prisage or butlerage of wines; which is considerably older than the customs, being taken notice of in the great roll of the exchequer, 8 Ric. I. still extant. Prisage was a right of taking two tons of wine from every ship importing into England twenty tons or more; which by Edward I. was exchanged into a duty of 2s for every ton imported by merchant-strangers, and called butlerage, because paid to the king's butler.
Source: wiktionary