Sir Edward Kelley (Kelly), apothecary, alchemist and medium, was born on 1st August 1555 in Worcester. In March 1582, Kelley called on astrologer and mathematician Dr John Dee at his home at Mortlake in Surrey. Kelley impressed Dee with his abilities as a medium, after Dee had been unsuccessful in making contact with angels. He worked closely with Dee for seven years, travelling around Europe and taking part in seances and allegedly communicating with angels in a special angelic language. Robert Parry, in his article John Dee: A Biographical Sketch, writes of how the two men received "various mysterious tables of letters and numbers, redolent, some say, of ciphers in use by those engaged in espionage at the time – yet which have never been deciphered" and that their angelic conversations resulted "in the transmission of an unique, sophisticated language (Enochian) with its own alphabet, syntax etc." Dee believed that the Enochian language was the language God had used to create the world and also the language He used to communicate with Adam and the angels.
From 1584-1589, Kelley and Dee settled in Prague, where they met Emperor Rudolph II and worked under the patronage of the Rosenberg family. There, they continued their work with angels and also experimented with alchemy. Kelley possessed a red powder which, with the help of the alchemical book The Book of Dunstan, he claimed he could make into a red tincture to transmute base metals into gold. Although he has been viewed as a charlatan, it is clear that he took his work very seriously, as did Dee. The men separated in 1589, with Kelley staying on the Continent and Dee returning to England.
Kelley was arrested in 1591,on the orders of the Emperor, allegedly for killing a man in a dual but more likely so that the Emperor could control Kelley, who had promised to produce gold for him. He was imprisoned in Křivoklát Castle but released after he'd promised to carry on with his alchemy. When his experiments failed, he was imprisoned again, this time in Hněvín Castle, and it is said that he died in 1598 from a fall while trying to escape.
Edward Kelley's treatises Tractatus duo egregii de lapide philosophorum una cum theatro astronomiae (1676) still survive today and have been translated into English as The Alchemical Writings of Edward Kelly (1893). You can download a PDF of Kelley's work at archive.org