Born son of a forester in Brandenburg, Dehmel studied philosophy in Berlin and Leipzig.
He married in 1889 but was divorced in 1899 and married again in 1901. In his Berlin years,
he lived a bohemian life in contact with Münch and Strindberg. He started the PAN
magazine in 1894 and took up a writing career publishing several works before the
first world war. He moved to Hamburg and, with his wife, founded a literary circle
embracing many leading figures.
He volunteered for war service and remained an active war supporter despite being
invalided out in 1916. He died of wound related causes in 1920.