On June 22,1941, Germany suddenly invaded the Soviet Union, starting the Great Patriotic War of 1941-45. Ukraine was one of the main strategic targets of the Wehrmacht eager to seize the USSR's industrially developed south. Still the Red Army's staunch resistance frustrated Germany's plans. The Battles of Kyiv, Odesa and Sevastopol (these three cities were titled "Hero-cities" after the war) slowed the Nazi offensive. In Ukraine the Nazi occupation regime was marked by special cruelty. In the years of the war its population dropped by 14.5 million. There were more than 200 concentration camps. Hundreds of thousands were put to death at the Yanivka camp in Lviv and in the Babi Yar ravine near Kyiv. Some 250 villages of Ukraine were burned together with their residents.
Nazi atrocities caused growing resistance from the Ukrainian people. Hie first partisan units appeared already in the summer of 1941. The biggest formations were led by S. Kovpak, O. Fyodorav and O. Saburov.
The Battle of Stalingrad, which fumed the tide of WW II, also marked the beginning of liberation of the Ukrainian lands. The entire territory of Ukraine was cleared of the aggressor in October 1944. For participation in battles for the liberation of Ukraine 3,755 men and officers of the Soviet Army were bestowed the title "Hero of the Soviet Union". The Ukrainian nation produced a number of prominent military leaders, among them R. Malynovsky, I. Chernyakhoysky, S. Tymoshenko, K. Moskalenko, P. Rybalko... War ace pilot I. Kozhedub was named Hero of the Soviet Union three times.
After the Second World War almost all Ukrainian territories were united within the USSR. Transcarpathian Ukraine was joined to the Ukr. SSR as a separate region in 1945. By a Decree of 1954 of the USSR Supreme Soviet the Crimea was given to Ukraine.
Ukraine's economy was restored over a period of five years after the war. Over the decades after WW II Ukraine showed good progress in all industries and agriculture. Its attainments in the cultural domain received world acclaim.