‘Danegeld’ encompasses two separate but related terms: ‘gafol’ (tribute), paid irregularly to appease and avert raiding Viking armies, particularly during Æthelred II’s reign, but seen as encouraging further attacks and the eventual Danish conquest of England (1013–16); and regulated ‘heregeld’ (army-tax), levied annually from 1012 to maintain Scandinavian mercenaries.
Ellis, Caitlin. "Danegeld". The Literary Encyclopedia. First published 04 January 2016
[http://www.litencyc.com/php/stopics.php?rec=true&UID=6960, accessed 10 February 2016.]