[1] In 1936, the government of Germany provided a considerable sum of money to reactivate a moribund project of archaeological excavation on the site of Olympia, Greece.
In 1939, Schleif worked as "General Trustee for securing of German cultural goods in the former Polish territory" together with Ernst Petersen in the plunder of the Warsaw archaeological museum in Łazienki Park.
He was suspended in September 1940 from the position of a general trustee in Poznań due to his misunderstanding of his function, because the Gestapo expected him to plunder public and private art and cultural objects, that he did not follow.
In contrast to some academics who were part of the Ahnenerbe, Schleif enjoyed a strong international reputation, something he shared with a handful of fellow Nazi archaeologists such as Herbert Jankuhn.
[5] On 27 April 1945, around 11 pm, Schleif killed his wife, Lora, and twin 18-month old sons Alexander and Konstantin before taking his own life.