The T-54 and T-55 tanks are a series of main battle tanks originally conceived as medium tanks that were designed in the Soviet Union. The first T-54 prototype appeared in March 1945, just as the Second World War ended. The T-54 entered full production in 1947 and became the main tank for armored units of the Soviet Army, armies of the Warsaw Pact countries, and others. T-54s and T-55s were involved in many of the world's armed conflicts during the late 20th and early 21st century.
The T-54/55 series eventually became the most-produced tank in history. Estimated production numbers for the series range from 86,000 to 100,000. They were replaced by the T-62, T-64, T-72, T-80, and T-90 in the Soviet and Russian Armies, but remain in use by up to 50 other armies worldwide, some having received sophisticated retrofitting.
