Who was elected leader of the UK Labour Party in September 2015?

Jeremy Corbyn was elected leader of the UK Labour Party in September 2015 due to his strong support among party members who were looking for a leader with a more radical and left-wing agenda. Corbyn's campaign focused on issues such as wealth inequality, austerity measures, and renationalization of public services, resonating with the party's grassroots supporters who were disillusioned with the centrist policies of the party under the previous leadership. This wave of anti-establishment sentiment and desire for change propelled Corbyn to victory, making him the leader of the Labour Party.