First Secretary of the Communist Party of Ukraine in the context of Nikolai Podgorny

The Union of Russia and Ukraine Tercentenary or the Reunification of Ukraine with Russia Tercentenary (Russian: 300-летие воссоединения Украины с Россией, 300-letiye vossoyedineniya Ukrainy s Rossiyei; Ukrainian: 300-річчя возз'єднання України з Росією) was a republic-wide celebration within the Soviet republics of Russia and Ukraine, starting in February 1954, in celebration of the union between Russia and Ukraine formed by the 1654 Pereiaslav Agreement.

In preparation for the event, a special Republican commission for commemoration of the union between Russia and Ukraine Tercentenary was formed, headed by the First Secretary of the Communist Party of Ukraine Alexei Kirichenko. A three-volume body of documents and materials titled as "Reunification of Ukraine with Russia" was published in 1953 in Moscow, prepared jointly by the History Institute of the Academy of Sciences of the Soviet Union, History Institute of the Academy of Sciences of the Ukrainian SSR, and the Ukrainian Directorate of Archives, and included 747 documents of the period between 1620 and 1654. The materials were prepared by a group of Soviet Russian and Ukrainian historians organized in 1952 and approved by the Central Committee of the Communist Party of the Soviet Union.

Lazar Moiseyevich Kaganovich (Russian: Лазарь Моисеевич Каганович; 22 November [O.S. 10 November] 1893 – July 25, 1991) was a Soviet politician and one of Joseph Stalin's closest associates.

Born to a Jewish family in Ukraine, Kaganovich worked as a shoemaker and joined the Russian Social Democratic Labour Party in 1911. During and after the 1917 October Revolution, he held leading positions in Bolshevik organizations in Belarus and Russia, and helped consolidate Soviet rule in Turkestan. In 1922, Stalin placed Kaganovich in charge of an organizational department of the Communist Party, assisting the former in consolidating his grip on the party. Kaganovich was appointed First Secretary of the Communist Party of Ukraine in 1925, and a full member of the Politburo and Stalin's deputy party secretary in 1930. In 1932–33, he helped enforce grain quotas in Ukraine which contributed to the Holodomor famine. From the mid-1930s on, Kaganovich variously served as the People's Commissar for Railways, Heavy Industry and Oil Industry. Following the outbreak of the Second World War, he was appointed a member of the State Defence Committee.