Also to be found on the other Voynich Wiki here [1]

Also known as Jiří Bareš, Georgius Barschius. He was born in 1585. He received his baccalaureate in 1602. He died in 1662.

Medieval European alchemist and antique collector from Prague, and the earliest confirmed owner of the Voynich Manuscript, about which he was in correspondence with Athanasius Kircher in the late 1630s, having owned the Manuscript for some time.

More information on the Wikipedia page [2] and the Voynich Manuscript Biographies page [3]: a mention here [4]. Details of the letter can be found here [5]. Wikidata page [6].