Dede was born 1935 in Nordenham-Blexen. His father was a Lutheran priest. After school Dede studied during the 1950s. Later Dede worked as a newspaper reporter in Papenburg, Gütersloh and Nordenham. Dede wrote several books over local history in northern part of Lower-Saxony (Butjadingen, Oldenburg, Bremerhaven, Stedingen, Jade, Wesermarsch) and a book over Jesus Jesus – schwul?, Die Kirchen, die Christen und die Liebe. Dede lives in Oldenburg.