Johannes Stadius

Johannes Stadius, also Estadius (Dutch Jan Van Ostaeyen, French Jean Stade; 1527 to 1579), was a Flemish astronomer, astrologer and mathematician, and one of the important late sixteenth century makers of ephemerides, the tables giving the positions of the Sun, Moon and planets at given times. Born on 1 May 1527 at Loenhout in the Duchy of Brabant to unmarried parents, he was educated at the Latin school of Brecht and studied mathematics, geography and history at the Old University of Leuven, where Gemma Frisius was one of his teachers, afterwards becoming a professor of mathematics there. In 1554 he went to Turin under the patronage of the Duke of Savoy, then worked in Cologne, Brussels and Paris, where he debated the trigonometrist Maurice Bressieu and made astrological predictions for the French court. In his Tabulae Bergenses of 1560 he called himself royal mathematician to Philip II of Spain and mathematician to the Duke of Savoy. His first work, the Ephemerides novae et auctae, published at Cologne in 1554 at the urging of Gemma Frisius, posited a link between mathematics and medicine and influenced Tycho Brahe and Nostradamus.