The Prague Spring , a political liberalization campaign originated by the reformist Slovak Alexander Dubček in Czechoslovakia, began on January  5, 1968 and ended on August 21 of 1968, when the Soviet Union and members of its Warsaw Pact allies invaded the country to halt the reforms.During the era of liberalization, the Communist Party of Czechoslovakia wanted to carry out reforms in order to reduce the power of Stalinization. Finally, the campaign was unsuccessful.