Alchemy arguably dates back to Alexandria, and there are many alchemical manuscripts dating through to the 13th and 14th century (though Lynn Thorndike noted that the 15th century was something of a fallow period). However, the modern organization The International Alchemy Guild traces its practical roots back to what was going in 16th century Bohemia, specifically with the work of Wilhelm von Rosenberg (their spelling) in Cesky Krumlov.
The Guild has put together a nice little historical piece on their website linking a lot of the famous alchemical names of the time to this specific milieu (though doubtless Voynich historian Rafal Prinke would view it as a somewhat simplistic rendering): so you’ll see Rudolph II, Hajek, Dee, Kelley, Horcicky, etc all passing by in quick succession… Enjoy!