Ancient map of Norway published in the XVII Century by Jan Jansson

Dioecesis Trundhemiensis Pars Australis by Johannes Janssonius (also known as Jan Jansson) is a finely detailed 17th-century map depicting the southern part of the Diocese of Trondheim (Trundheim), in what is now central Norway. Originally published in Jansson’s grand atlas Atlas Novus, the map captures the rugged terrain, fjords, and ecclesiastical boundaries of the region during the early modern period. Latin place names and topographical features are meticulously engraved, and the composition typically includes a decorative cartouche, compass rose, and ornate scale bars. The map was copperplate-engraved and often hand-colored, combining geographic precision with Baroque embellishment.

Jan Jansson (1588–1664) was a leading Dutch cartographer and publisher who inherited and expanded the legacy of the Hondius family, producing some of the most lavish atlases of the 17th century. Working from Amsterdam, he published a wide array of maps covering Europe and beyond, often collaborating with or competing against the Blaeu family. Jansson’s work is known for its elegant styling, clear geography, and artistic flourishes. His ecclesiastical maps, like this one, reflect a growing interest in both religious and regional mapping during the post-Reformation period.