[[St. Brice's Day Massacre]], ordered by [[Ethelred the Unready]], in which many Danes including Swenn's sister were killed. Sweyn later invaded England, but only ruled England for a few weeks before his death. Ethelred resumed the throne. | [[St. Brice's Day Massacre]], ordered by [[Ethelred the Unready]], in which many Danes including Swenn's sister were killed. Sweyn later invaded England, but only ruled England for a few weeks before his death. Ethelred resumed the throne. |