Soon after, he joined the circle of artists that formed around the sculptor George Minne in the Flemish village of Sint-Martens-Latem.
[2] His large format painting "The Harvest" was displayed in Paris in 1910 and brought a letter of appreciation from Henri Matisse.
The following year, he left Berlin for good and settled near Brüggen, taking a wing of Schloss Dilborn [de] for his studio.
Regular visitors there included Heinrich Campendonk, Erich Heckel, Franz Marc and August Macke.
He was inducted into the army and assigned to an artillery regiment but, after being in combat only briefly and being exposed to poison gas, he was engaged as a war artist instead.