Developed by Capcom, Street Fighter II was released in 1991 as a sequel to the original 1987 Street Fighter and it’s credited for starting the fighting game boom during the 1990s. Its success led to the production of a series of updated versions, each offering additional features and characters over previous versions, as well as several home versions. The roster initially included Ryu and Ken plus six new characters from different nationalities. [Info from Wikipedia]
In EGM issue #33 there was an interesting article with some early character designs, that show different versions of Vega (Balrog), Chun Li and Blanka.
Thanks to Celine for the scan!