Danegeld
Danegeld , noun
[Anglo-Saxon danegeld. See Dane, and Geld, n.]
(Eng. Hist.) An annual tax formerly laid on the English nation to buy off the ravages of Danish invaders, or to maintain forces to oppose them. It afterward became a permanent tax, raised by an assessment, at first of one shilling, afterward of two shillings, upon every hide of land throughout the realm. — Wharton's Law Dict. Tomlins
Also: Danegelt