Eastern Old Japanese

Eastern Old Japanese (abbreviated as EOJ; Japanese: 上代東国方言, 上代東国語) is a group of heterogenous varieties of Old Japanese, historically spoken in the east of Japan, in the area traditionally called Togoku or Azuma.

Eastern Old Japanese constitutes a branch of the Japanese subgroup of the Japonic languages (Insular Japonic), with the other varieties of Old Japanese, which all descend from proto-Japanese (separate from Proto-Ryukyuan, following the classification used by Kupchik (2011).

Eastern Old Japanese is mainly attested through poems collected in several anthologies written during the 8th century:

All this would give a total of 242 short poems and one long poem according to Alexander Vovin (2014).

This variety is geographically opposed to Western Old Japanese and Kyūshū Old Japanese. It was spoken to the east of Nara, the capital during the eponymous Nara period, approximately in the current Kantō region, Chūbu region and Tōhoku region, which was collectively referred to as Azuma.

Eastern Old Japanese was not a unified variety but rather a collection of dialects. Their demarcation differs depending on the author.

For example, Bjarke Frellesvig (2010) distinguishes three dialect areas:

He states that these dialects form a continuum with the varieties of Nara Old Japanese, with North Eastern Old Japanese constituting the most divergent variety. However, the majority of songs and poems do not have information on their provenance.