The Centre Union (EK, Greek: Ένωσις Κέντρου, Enosis Kentrou) was a Greek political party, created in 1961 by George Papandreou, senior. The party was elected to power in 1963, with Papandreou as Prime Minister. In 1965, King Constantine forced Papandreou from the office following the Apostasia of 1965 plan, designed by him and executed by Center Union's politician Konstantinos Mitsotakis. He then formed a new government using the apostates, ex-members of EK, and installed Georgios Athanasiadis-Novas as prime minister. Athanasiadis attempted to gain a vote of confidence in parliament, but the EK party was split in two, and a political crisis ensued that led to the period of the Greek military junta of 1967-1974.