The first definitive cases of alcohol distillation come Southern Italy in the 12th Century.  Around the same time, the Chinese may have also discovered distillation independently.  The record of one early distillation  method from the 13th Century, Fractional distillation, was written in code – I, for one, can understand why: if I’d discovered a better method of of extracting this new beverage substance, alcohol, I’d want to protect that method too.  Alcohol was initially used as medicinal treatment for a range of ailments, and its use a remedy for the Black Death is partly responsible for the spread of drinking alcohol across Europe.  Some time in the late-14th to early-15th Century, methods for distilling from wheat, barley, and rye were discovered, making alcohol production significantly cheaper and more accessible.

 

Source: Wikipedia