A Marvellous Connection: Longomontanus’ Battle With the Latitudes of Mars

This paper deals with Longomontanus’ theory of latitudes of Mars, as it is extant in his Astronomia Danica. I will show how the solution that Longomontanus devised to solve the longitude problems presented by Tycho’s non-bisected model allowed him to achieve very good latitude predictions, without correcting the basic underlying values that were at the root of Tycho’s difficulties regarding latitudes.