2d ed
"Sumer Is Icumen In" (also called the Summer Canon and the Cuckoo Song) is a medieval English rota (a type of vocal round of the 13th and 14th centuries).
The title translates approximately to "Summer Has Come In" or "Summer Has Arrived". The song is composed in the Wessex dialect of Middle English. Although the composer's identity is unknown today, it may have been W. de Wycombe. The manuscript in which it is preserved was copied between 1261 and 1264 (Wulstan 2000, 8).
http://en.wikipedia.org/wiki/Sumer_Is_Icumen_In
Jamieson B. Hurry (1857 - 1930) was an English physician and author who published several works on the history of Reading and its abbey, where the earlest known copy of the "Sumer is cumin in" was discovered.
This description of 'Sumer is icumen in' was originally published at the time of the unveiling at Reading abbey of a memorial tablet, bearing a facsimile of the canon. The score in the present edition is in modern notation, edited by W. S. Rockstro, author of the article, Sumer is icumen in" in Grove's Dictionary of music. The canon is preserved in ms. Harl. 978 in the British Museum
Signed by author"