What is "butlerage"

Butlerage \But"ler*age\, n. (O. Eng. Law) A duty of two shillings on every tun of wine imported into England by merchant strangers; -- so called because paid to the king's butler for the king.
--Blackstone.

n. (context legal archaic English) A duty formerly paid to the king's butler on every tun of wine imported into England by foreign merchants.

A butlerage was a duty of two shillings on every ton of wine imported into England by merchant strangers; so called because it was paid to the king's butler for the king. The tax was first implemented in 1302 and stopped being levied in 1809.