His father, originally from Hamburg, moved the family back to Germany when John Horneburg was still a child.
From 1918, the family lived in Stralsund, where John Horneburg ran an antiques store in Semlower Straße.
When Hitler came to power in Germany in 1933, Horneburg was persecuted under Nazi racial laws because of his Jewish heritage.
He was forced to give up his business in 1938 due to the decree to eliminate Jews from German economic life and ultimately had to sell his two houses in Stralsund.
John and Karoline Horneburg moved to Hamburg in March 1940; they returned after the war and lived in the house in Göhren until their deaths.