In 1908, Hodler met Valentine Godé-Darel, who became his mistress. She was diagnosed with cancer in 1913, and the many hours Hodler spent by her bedside resulted in a remarkable series of paintings documenting her decline from the disease. Her death in January 1915 affected Hodler greatly. He occupied himself with work on a series of about 20 introspective self-portraits that date from 1916. (https://en.wikipedia.org/wiki/Ferdinand_Hodler)