Just had the Oxford Dictionary out.

Sixteenth century (give or take a year)

Soul description equates to a Man (not woman) having Soul.......

Anyway Soul with regard to our chosen style of tune BEFORE northern was coined by the Great Dave Godin was attributed for the first time by whom....the truly first "SOUL" record/Release Gotta be in the USA anyway or not ?ATB Steve

An excellent read about where you're coming from is, Sweet Soul Music by Peter Guralnick published by MOJO books is compelling and informative reading