Icelandic Commonwealth
The Icelandic Commonwealth was established in 930 CE by refugees from Norway who had fled the unification of that country under King Harald Fairhair. The Commonwealth consisted of a number of clans run by chieftains, and the Althing was a combination of parliament and supreme court where disputes appealed from lower courts were settled, laws were decided, and decisions of national importance were taken. One such example was the Christianisation of Iceland in 1000, where the Althing decreed that all Icelanders must be baptized into Christianity, and forbade celebration of pagan rituals. Contrary to most states, the Icelandic Commonwealth had no official leader.