Which Turkish leader abolished the Institution of Caliphate?

Which Turkish leader abolished the Institution of Caliphate?

کس ترک رہنما نے خلافت کا ادارہ ختم کیا؟
Explanation
It was further undermined when Mustafa Kemal Atatürk drove the Greeks from western Asia Minor in 1922 and deposed the Turkish sultan Mehmed VI in the same year.
The movement finally collapsed when Atatürk abolished the caliphate altogether in 1924.