 In 1945 Koenig-Warthausen returned to a family estate at Sommershausen, near Biberach, where he farmed and was a member of several organisations promoting local agriculture.He sold the estate in 1973 and retired to a house overlooking Lake Maggiore, in the village of Brezzo di Bedero, Italy.Koenig-Warthausen died in Munich on 15 December 1986, and is buried at the cemetery in Niederaudorf, nr.