After a summer with the Skagen Painters in 1884, he returned to Kiel where he painted and sketched the old town and the harbor, publishing many of his illustrations in local magazines.
Thanks to his studies at the academies of Weimar, Munich and Kassel, he became a skilled draftsman and landscape painter, supplemented by extensive travels to Italy, Algeria, France, Norway, Belgium and the Netherlands.
[1] In 1882, Stoltenberg became associated with the painters who gathered each summer in Egernsund on the north coast of Flensburg Firth to paint and sketch in the open air.
[2][3] After making a name for himself as a plein air painter, in 1889 Stoltenberg married Anna Scharenberg from a well-to-do Hamburg family, settling in his home town of Kiel.
Of particular note are his sketches of the old town and the fishing village of Alt Ellerbek, not to mention his illustrations of the latest developments in marine engineering.