Political Organization of Iceland in Landnámabók, Part 1, Chapter XXI

The Norse Chiefs who settled in Iceland finding the country uninhabited, solemnly took possession of the land, directing their landtake by the omens of the drifting ashore of the high seat pillars, &c., and then in order to found a community, they built a temple and called themselves by the name of goði or hof goði (temple-priest), and thus the temple became the nucleus of a new community, which was called goðorð. Many independent goðar and goðorð sprung up throughout all the country, until about the year 930 the Althing was erected where all the petty sovereign chiefs goðar entered into a kind of league, and formed a general government for the whole Island. In A.D. 964 the constitution was settled; the number of goðorð being fixed at three in each thing (shire), and three things in each of the other three quarters, but four in the north; thus the number of goðar came to be nominally thirty-nine, really thirty-six as the four in the north were reckoned out as three.