The Viking Berserkers
The Berserker Vikings lived in many parts of north western Europe but they originated in Sweden and Norway. There is no set date when they originated but in 1015, Jarl Eiríkr Hákonarson of Norway outlawed berserkers, and Grágás, the medieval Icelandic law code, sentenced berserker warriors to be banned. By the 12th century, berserkers had been completely disbanded.
The berserks didn't use a single definite form of government but they did use forms of trading with other tribes and cultures. They traded for many things including clothes, food and weapon materials. There was no form of government except for trading goods and valuable items for other things.