England had been ravaged by Danish raids every year from 997 to 1001, and in 1002 the king was told that the Danish men in England "would faithlessly take his life, and then all his councillors, and possess his kingdom afterwards." In response, he "ordered slain all the Danish men who were in England."

Historians believe there was significant loss of life. Among those thought to have been killed were Gunhilde, who may have been the sister of King Sweyn I of Denmark. Whether driven by vengeance or simply availing a pretext — Sweyn resumed harrying the English kingdom in the following years. By 1013, Sweyn had driven Ethelred to Normandy and ruled all of England, welding together a Norse empire fringing the whole north of Europe.