Kurt Schwitters, Dada Künstler - Merzbau in Hannover, Germany. Photo by Wilhelm Redemann, 1933. Schwitters worked on the Hanover Merzbau from around 1923 until 1937, when he fled to Norway to escape the threat of Nazi Germany. Sadly, in 1943, while he was in exile, it was destroyed in an Allied bombing raid. This original Merzbau was gone forever.