Tycho Brahe, a Danish aristocrat, takes up residence at Wandesburg Castle in autumn 1597 at the invitation of the wealthy German humanist writer and statesman Heinrich Rantzau, the governor of Holstein, a prolific astrologer and a celebrated book collector.

Here Tycho prints a small first edition of Astronomiæ instauratæ mechanica, which contains illustrations and descriptions of the most important of the instruments he has developed, as well as a brief survey of his theoretical results.

Along with his catalogue of over one thousand stars, the book is sent to a wide range of colleagues and princes.

Europe’s leading astronomer is searching for a new employer.