Christoffer Dybvad

Christoffer Dybvad, born about 1578 and dead in 1622, was a Danish mathematician, the son of Dr Jørgen Dybvad, born in Copenhagen in 1577 or 1578. He became a student very young and by 1594 appears as respondent at his father's disputations. In 1599 he went abroad on the royal travel grant for a medical student, took a doctorate at Caen in Normandy about 1601 and studied for a time at Leiden, where in 1602 he published in Danish his first mathematical work, Decarithmia, on decimal fractions, notable for trying to replace the usual Greek technical terms of mathematics with Danish words. He repeatedly sought a post at the University of Copenhagen without success and spent years in the Netherlands, France and Italy, returning to Denmark about 1612. In 1619 he went to Bergen, where bold remarks on the nobility and the constitution led to his arrest in 1620; the university sentenced him on 22 December 1620 to lifelong imprisonment, and he died in 1622 in the tower called Folen at Kalundborg Castle.