title: Georgios Papadopoulos
context: Georgios Papadopoulos (/ˌpæpəˈdɒpəlɒs/; Greek: Γεώργιος Παπαδόπουλος [ʝeˈorʝios papaˈðopulos]; 5 May 1919 – 27 June 1999) was the head of the military coup d'état that took place in Greece on 21 April 1967, and leader of the junta that ruled the country from 1967 to 1974. He held his dictatorial power until 1973, when he was himself overthrown by his co-conspirator Dimitrios Ioannidis.
question: How long did Georgios Papadopoulos lead Greece?
answers: until 1973