Regiomontanus (1436‒1476)

Regiomontanus, name adopted by Johann Müller, a celebrated German astronomer and mathematician, born at Königsberg, in Franconia; appointed professor of Astronomy in Vienna (1461); sojourned in Italy; settled in Nüremberg, where much of his best work was done; assisted Pope Sixtus IV. in reforming the Calendar; was made Bishop of Ratisbon; died at Rome; was regarded as the most learned astronomer of the time in Europe, and his works were of great value to Columbus and other early navigators (1436‒1476).

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)