Ezo (蝦夷?, also spelled Yezo or Yeso) is a Japanese name which historically referred to the lands to the north of Japan. It was used in various senses, sometimes meaning the northern Japanese island of Hokkaido, and sometimes meaning lands and waters farther north in the Sea of Okhotsk, like Sakhalin and the Kuril Islands. The word "Ezo" can also refer to the peoples that the Japanese encountered in these lands, referred to in modern times as the Ainu people.
The "Ezo" spelling reflects the pronunciation in Modern Standard Japanese. The spelling "Yezo" reflects its pronunciation circa 1600 AD, when Europeans first came in contact with Japan. It is this historical spelling that is reflected in the scientific Latin term yezoensis, as in Fragaria yezoensis and Porphyra yezoensis.
The first published description of Ezo in the West was brought to Europe by Isaac Titsingh in 1796. His small library of Japanese books included Sangoku Tsūran Zusetsu (三国通覧図説 An Illustrated Description of Three Countries?) by Hayashi Shihei. This book, which was published in Japan in 1785, described the Ezo region and people.
In 1832, the Oriental Translation Fund of Great Britain and Ireland supported the posthumous abridged publication of Titsingh's French translation of Sankoku Tsūran Zusetsu. Julius Klaproth was the editor, completing the task which was left incomplete by the death of the book's initial editor, Jean-Pierre Abel-Rémusat.
- Batchelor, John. (1902). Sea-Girt Yezo: Glimpses at Missionary Work in North Japan, pp. 2-8.
- Nussbaum, Louis-Frédéric. (2005). "Ezo" in Japan Encyclopedia, p. 184.
- WorldCat, Sangoku Tsūran Zusetsu; alternate romaji Sankoku Tsūran Zusetsu
- Cullen, Louis M. (2003). A History of Japan, 1582-1941: Internal and External Worlds, p. 137., p. 137, at Google Books
- Klaproth, Julius. (1832). San kokf tsou ran to sets, ou Aperçu général des trois royaumes, pp. 181-255., p. 181, at Google Books
- Cullen, Louis M. (2003). A History of Japan, 1582-1941: Internal and External Worlds. Cambridge: Cambridge University Press. 10-ISBN 052182155X/13-ISBN 9780521821551; 10-ISBN 0521529182/13-ISBN 9780521529181; OCLC 50694793
- Hayashi, Shihei. (1786). Sangoku Tsūran Zusetsu (三国通覧図説 An Illustrated Description of Three Countries?). Edo: Manuscript. OCLC 44014900
- Klaproth, Julius. (1832). San kokf tsou ran to sets, ou Aperçu général des trois royaumes. Paris: Oriental Translation Fund of Great Britain and Ireland. OCLC 2563166; also OCLC 561284561