Bulgaria, officially the Republic of Bulgaria, is one of the oldest states in Europe. It is located in the eastern portion of the Balkan Peninsula. It is bordered by Romania to the north, Serbia and North Macedonia to the west, Greece and Turkey to the south, and the Black Sea to the east. Its capital, Sofia, is the largest city and located near the geographic center of the Balkan region. Though Bulgaria is part of the European Union, it has not fully adopted the euro. Bulgaria joined the European exchange rate mechanism (ERM II) on July 10, 2020. Instead of the euro, Bulgaria use the lev. The word lev is the old Bulgarian word for lion.
Early lev banknotes were used as silver and gold certificates. In 1904, silver and golden lev banknotes employed the Orlov printing method as an anti-counterfeiting measure. These banknotes had intricate design patterns and many colors. The first lev banknotes that were not convertible to silver and gold were printed by the American Bank Note Company and issued by the Bulgarian National Bank in 1922. These banknotes depicted different aspects in Bulgarian culture. The first lev to feature an authority figure is the 1924 5,000-lev banknote, which had Tsar Boris III on its obverse side and Hristo Botev on its reverse side. In 1941, Bulgaria was forced to join the Axis forces during the Second World War. Subsequent banknotes were printed by Giesecke and Devrient until 1943, when Tsar Boris III died of a heart attack. Afterwards, banknotes were printed by the State Printing House and featured Tsar Simeon II. When Bulgaria was invaded by the Soviet Union in 1944, the monarchy was abolished and a communist regime was installed. The banknotes that were produced at the time featured the Soviet style coat of arms and highlighted various trades and workers on the reverse side. In 1952, the Bulgarian National Bank issued state treasury notes that used the new lev alongside banknotes that featured Georgi Dimitrov, the first communist leader. After the fall of the communist regime in 1990, Bulgaria issued new banknotes that featured famous Bulgarians and their works. Since then, Bulgarian notes featured prominent Bulgarians on their banknotes. The first banknote to use the holographic stripe was the 1994 2,000-lev banknote. In 2005, the Bulgarian National Bank issued a commemorative 20-lev banknote to celebrate the 120th anniversary of the first Bulgarian banknote. This 20-lev banknote is the first to use the Giesecke & Devrient varifeye security thread, a wide security thread that incorporates a plastic-covered window in a paper substrate.