In 1906, he met Doris Große, who was his favoured model until 1911. Between 1907 and 1911, he stayed during the summer at the Moritzburg lakes and on the island of Fehmarn (which he revisited until 1914) with other Brücke members; his work featured the female nude in natural settings. In 1911, he moved to Berlin, where he founded a private art school, MIUM-Institut, in collaboration with Max Pechstein with the aim of promulgating "Moderner Unterricht im Malen" (modern teaching of painting). This was not a success and closed the following year, when he also began a relationship with Erna Schilling that lasted the rest of his life.