Wenceslaus IV of Bohemia
Jan Šindel (1370s – between 1455 and 1457), also known as Jan Ondřejův ( or "Joannes de Praga"), was a Czech medieval scientist and Catholic priest. He was a professor at Charles University in Prague and became the rector of the university in 1410. He lectured on mathematics and astronomy and was also a personal astrologer and physician of kings Wenceslaus IV of Bohemia and his brother Holy Roman Emperor Sigismund.