EJ7DD 1928 Jugoslavia

Operator: Stjepan Liebermann, also: YU7UU
He admits he does not have a valid license (on the back of his card).

The Kingdom of Yugoslavia was formed in 1922, unifying Serbia, Slovenia and Croatia. It was invaded by the Axis powers in 1941, and militant separatists proclaimed some independent states within, blessed by Nazi Germany. These fake states committed attrocities to other slavic ethnic groups and all the groups also targeted by Nazi racial policies. 
Starting by the proclamation of partisan resistance in 1943, and finalized by the abolishment of monarchy in 1945, Yugoslavia was renamed the People's Republic of Yugoslavia until its resolvement through the civil war in the early 2000's.

Stjepan (Stefan) Liebermann (1904-1942), Zagreb Croatia Yugoslavia, DE0563, UN7DD, EJ7DD, YU7UU. He started unlis operation in 1927 and by 1930 he had worked over 70 countries and was a member of the WAC club. On a 1933 QSL he spelled his call as: Yugoslavia –7 –Ultra –Unlis. In 1939 he was the most famous YU station, and listed in [callbook 1939] as contact for handling QSL's to YU under cover. In 1942 he was killed in the notorious Jasenovac concentration camp (U Logoru) run by the Ustasha government. The militant and fashist revolutionary organization Ustasha ruled an “Independent State of Croatia” in German-occupied Yugoslavia from 1941-1945, backed by Hitler and Mussolini. They committed large-scale genocide against ethnic Serbs and all groups also under prosecution by the Nazis.

QSL courtesy of VA3DN
Info courtesy of K6EE