Mustafa Kemal Atatürk was the founder and first president of Turkey who led the country's transformation into a modern republic after World War I. As a military officer, he defended Turkey against Allied invaders and then established the Grand National Assembly to pursue independence. On October 29, 1923, Atatürk proclaimed the Republic of Turkey and embarked on a program of dramatic modernization, secularizing the government, abolishing the caliphate, giving equal rights to women, and advancing Turkey's economy and education system. He served as president until his death in 1938, leaving a profound legacy as the father of modern Turkey.