On October 29, 1923 Mustafa Kemal officially confirmed Turkey as a republic (Türkiye Cumhuriyeti), now commemorated annually as the Republic Day of Turkey. From the article:
"Turkey marks 96th anniversary of Republic Day - Turkey News
ANKARA
Turkey marks 96th anniversary of Republic Day
Millions of Turks across the country and abroad are celebrating on Oct. 29 the 96th anniversary of the proclamation of the Republic of Turkey.
Mustafa Kemal Atatürk, the republic’s founder, on Oct. 29, 1923, officially declared the name of the nation and proclaimed the country’s status as a republic.
A vote then took place in the Grand National Assembly, and Atatürk was elected the first president of the Republic of Turkey by a unanimous vote.
Since then, Turkey celebrates Republic Day every Oct. 29.
How the Turkish Republic was established
How the Turkish Republic was established
Republic Day will be celebrated in all provinces of Turkey and the country’s representations abroad.
A government ceremony in the capital Ankara, art events and fireworks in Istanbul, concerts and torchlight processions in the Aegean province of İzmir are among the symbols of Republic Day celebrations in Turkey.
Many school children will present special performances for their parents and teachers.
With the participation of citizens, a march will take place from the current parliament building in the Bakanlıklar neighborhood of the Çankaya district to the Republic’s first parliament building in the Ulus district, which is currently used as the Independence War Museum.
Thousands of people, including high-level state officials, will pay their visits to Mustafa Kemal Atatürk’s mausoleum, also known as Anıtkabir.
President Recep Tayyip Erdoğan laid a wreath at Anıtkabir and sign the official memorial book as is the case every year.
Following the ceremony at Anıtkabir, he received greetings at the Presidential Complex.
Meanwhile, Erdoğan released a message on Oct. 28 to mark the 96th anniversary of the Republic, saying that “Turkey has the power, capability, and determination to overcome all problems.”
“I remember with respect all our heroes, to start with Gazi Mustafa Kemal Atatürk, who contributed to the victory in our Independence War with a century-old glorious past and to the foundation of our new state. Turkey is a country that has maintained its struggle for independence from beginning till the end through the National Assembly, which represents the national will. I would like to express my gratitude to all the deputies who have worked for the development, strengthening and progress of our country so far from our Grand National Assembly, which will celebrate its 100th anniversary next year,” read the message.
“Turkey, with its long history, its deeply rooted governing experience and almost century-long accumulations as a Republic, has the power, capability and determination to overcome all these problems. As a matter of fact, with the help of Allah, with the support of our nation, we foiled all the traps set against our country one by one,” the message also said."