[Fiji Hill]

For 20 years, Sweyn, a "murderous character" who deposed his father Harold Bluetooth, waged war on England.

In the 1970's, science fiction writer John Norman wrote a series of novels that take place on a planet called Gor, where life resembles that of ancient Greece and Rome, Aztec Mexico, Viking-ruled Scandinavia, etc., with some exotic beasts and space aliens thrown in. Two of his Viking-type characters are named Ivar Forkbeard and Sweyn Bluetooth.

[SunkenCiv]

I always liked the covers of those paperbacks.