Ari Þorgilsson (1067/1068 – 9 November 1148; Old Norse: [ˈɑre ˈθorˌɡilsˌson]; Modern Icelandic: [ˈaːrɪ ˈθɔrˌcɪlsˌsɔːn]; also anglicized Ari Thorgilsson) was Iceland's most prominent medieval chronicler.
[1][2] Ari was a part of the Haukdælir family clan and studied in the school in Haukadalur as a student of Teitur Ísleifsson (the son of Ísleifur Gissurarson, first bishop of Iceland).
It is believed that Ari later became a Christian priest in Staður by Ölduhryggur, now known as Staðastaður, but otherwise little is known about his life, despite the fact that he is one of the very few medieval writers who wrote down his family history.
[3][4] Íslendingabók is the only work that with evidence for his authorship,[5] but he is accredited with numerous articles of knowledge and is believed to have had a major part in the writing of Landnámabók, which chronicles the settlement of Iceland.
In Iceland's First Grammatical Treatise, written around 1160 AD, he is referred to with respect as an exceptional man, since the tradition of writing was not firmly established at the time.