Answer
Tsipras succeeded Alekos Alavanos as leader of Syriza in 2012. He led Syriza to victory in the 2015 Greek legislative election, becoming Prime Minister. In 2015, he negotiated a deal with the European Union and International Monetary Fund to reduce the Greek debt burden, but the deal was unpopular with many Greeks and Tsipras's popularity declined. In 2019, he was defeated in the Greek legislative election by Kyriakos Mitsotakis.