Craftsman and mathematician born in Munich. Worked in London from 1524 until his death. Appointed astronomer and clockmaker royal under the reign of Henry VIII, who showed a great interest in cosmography and overseas ventures. Taught astronomy and the "doctrine of the sphere" at Oxford. His sundials demonstrate his geometrical expertise and clockmaking skill. Volunteered to produce a map of England for the planned new edition of Claudius Ptolemy's (mid-2nd C. C.E.) Geography.