Gothus studied at the german Rostock university, where a friend of Tycho Brahe, the Scotsman Duncan Lidell, lectured in astronomy. Lidell's lectures on the Ptolemean, the Tychonian and the Copernican systems made Gothus at least a century ahead of his contemporaries in Sweden. He later continued his studies at several other german universities.

He was appointed professor in 1593, when Uppsala University was reinstated, and began his lectures the following year on astronomy, trigonometry and algebra. He mainly used the book Theoricae novae planetarum by Georg Purbach for his lectures in astronomy.

He was later appointed bishop of Strängnäs, and finally archbishop of Sweden.