Explanation:
The citizens of modern-day Russia and Bulgaria have been in contact for centuries.[1] The Cyrillic alphabet originated in the 9th century First Bulgarian Empire and was later accepted by the Orthodox Slavic countries as their standard alphabet. Both nations had the tradition of calling monarchs Tsars, a Slavic word for Emperor that also originated in Bulgaria. Russia helped Bulgaria gain sovereignty from the Ottoman Empire. The Bulgarians then built an Orthodox church in Sofia named after the Russian saint Alexander Nevsky in honor of the Russian soldiers who helped Bulgaria during that war.
Relations between two started to worsen when Russia refused to diplomatically support Bulgaria in the Bulgarian unification and the following Serbo-Bulgarian War.[2] This had a serious impact on Bulgarian–Russian relations, which continues to even modern day.
20th century
Bulgaria and Russia's relations continued to fall as Bulgaria accused Russia of meddling into its internal affairs, a fact that contributed to growing alliance between Tsarist Russia and Serbia. This led to antagonism between Bulgaria and Russia even when Russia motivated Bulgaria to form an alliance with Montenegro, Serbia and Greece to drive the Austrians away. When Bulgaria got a chance to occupy Constantinople during the First Balkan War against the Ottomans, Russia opposed Bulgarian military actions.[3][4] Russia also refused to condemn Serbia and Greece for attacking Bulgaria in the consequent war. Tensions between Bulgaria and Russia eventually erupted in the World War I when Bulgaria sided with German Empire over the promise to regain its lost soil. Eventually, Bulgaria and Russia suffered heavy military losses for their wars, and Bulgarian–Russian relations severed. It was not until 1930s that saw Russia, as Soviet Union, established relations with Bulgaria.[5]
In World War II, Bulgaria started as a member of the Axis powers,[6] but when the Soviets invaded the Balkans, Bulgaria joined the Soviet side.[7] The Soviet Red Army backed the Bulgarian coup d'état of 1944 which brought communists to power. From 1945 to 1948, the country became entrenched within the Soviet sphere of influence under the control of the Bulgarian Communist Party (BCP) which oversaw a program of Stalinization in the late 1940s and 1950s,[8] and joined the Warsaw Pact in 1955.[8] Political repression was widespread.[8] Bulgaria became highly dependent on Soviet patronage. Soviet technical and financial aid enabled it to rapidly industrialize. The USSR provided Bulgaria with energy and a market for its goods.[9] Bulgaria also received large-scale military aid from the Soviet Union, worth USD $16.7 billion between 1946 and 1990.[10] Bulgaria remained part of the Soviet bloc until 1989, when the BCP began to drift away from the USSR. The first multi-party elections were held in 1990 and the BCP lost power in elections the following year.[8]
Georgi Ivanov, a military officer from Bulgaria became the first Bulgarian to reach outer space when he boarded Soyuz 33 along with Soviet cosmonaut Nikolai Rukavishnikov. Bulgarian scientists were involved in preparations for the flight. During this era, Bulgaria was led by Todor Zhivkov, a close friend of Nikita Khrushchev.