  Regius was born in Utrecht, The Netherlands (the Republic of the Seven United Netherlands at the time), on 29 July 1598, into a wealthy family of brewers, and died on 19 February 1679 in the same city. Following initial studies in Arts at the University of Franeker, he studied medicine at Groningen and Leiden, and subsequently at the University of Montpellier (France). In 1623 he received his MD from the University of Padua (Italy). Regius was appointed town physician in Utrecht on his return there in 1625 and, following a period as headmaster of the Latin School at Naarden (where he was challenged about his religious orthodoxy as a Calvinist), he returned to Utrecht in 1634 and was re-appointed town physician in 1637. The Illustrious School of Utrecht had become a university in 1636 and, two years later, Regius was appointed ‘extraordinary’ Professor of Theoretical Medicine and Botany (equivalent to an associate professor, who was paid a significantly reduced salary). The following year, 1639, he was promoted to full professor. In 1640 Regius was awarded a salary increase, on the understanding that he would provide extra lectures to his students on natural philosophy. Since there were already professors of philosophy, mathematics, and theology in place at Utrecht, all of whom were senior to Regius, this extension of his contract included the seeds of subsequent controversies about philosophical and theological theses, and of disputes about disciplinary boundaries at the University.