When did the letter J enter the English alphabet?

The first English-language book to make a clear distinction between I and J was published in 1634 (Ref). Its use in the English alphabet followed, the letter J was the last of the 26 letters to be added to the English Alphabet. Its emerging distinctive use dates back to Middle High German, originally being a typographical flourish or swash character on the Roman i. The Italian: Gian Giorgio Trissino (1478-1550) was the first to explicitly distinguish I and J as representing separate sounds in 1524 with his "Trissino's epistle about the letters recently added in the Italian language." [Ref: Hogg, Richard M.; Norman Francis Blake, Roger Lass, Suzanne Romaine, R. W. Burchfield, John Algeo (1992). The Cambridge History of the English Language. Cambridge University Press. pp. p.39. ISBN 0521264766. http://books.google.com/books?id=CCvMbntWth8C.]