Complex sentence: Upon Baresch's death, the manuscript passed to his friend Jan Marek Marci (1595--1667) (Johannes Marcus Marci), then rector of Charles University in Prague, who a few years later sent the book to Kircher, his longtime friend and correspondent.
Split into simpler sentences: Upon Baresch's death, the manuscript passed to his friend Jan Marek Marci (1595--1667; also known as Johannes Marcus Marci), then rector of Charles University in Prague. A few years later Marci sent the book to Kircher, his longtime friend and correspondent.