Leonhard was born in 1913 in Emden, Germany. Second child of Marianne (born as de Beer) and Adolf Gössels, was brother of Theda (1912) and Manfried (1915).

In 1933 the Gössels family moved to Amsterdam with his grandmother Regina de Beer. During the nazi occupation, Leo worked as office clerk for the Joodsche Raad.

Regina de Beer (born as Isaak), Velbert, February 18^th 1861 – Sobibor, July 1943

Marianne Gössels (born as de Beer), Emden, December 19^th 1890 – Sobibor, July 1943

Adolf Gössels, Emden, November 4^th 1882 – Sobibor July 1943

Theda Klepman (born as Gössels), Emden, January 1^st 1912 – Auschwitz April 1943

Joseph Klepman, Amsterdam, June 1^st 1917 – Auschwitz, April 1943

Leonhard Gössels, Emden, April 4^th 1913 – Auschwitz, January 1943

Manfried Gössels, Emden, November 9^th 1915 – Auschwitz, March 1944

Sara Gössels (born as Agtsteribbe), Amsterdam, June 1^st 1908 – Auschwitz, November 1943