Turkey's Recep Tayyip Erdogan ushered in the new, executive presidential system he had long campaigned for by putting his son-in-law in charge of the economy and promising greater overhaul of a country he has dominated for 15 years.

Hours after he was sworn in with sweeping new powers at a ceremony in the capital of Ankara, Erdogan named Berat Albayrak as the treasury and finance minister in his new cabinet.

The announcement - and the absence of familiar, market-friendly ministers from the cabinet - helped to send the lira sharply lower.

Erdogan, the most popular and divisive leader in recent Turkish history, has now formally become the most powerful leader since Mustafa Kemal Ataturk founded the republic from the ruins of the Ottoman Empire.

Just as Ataturk transformed an impoverished nation at the eastern edge of Europe into a secular, Western-facing republic, Erdogan has fought to bring Islamic values back into public life and lift millions of pious Turks - long ostracised by the secular elite - out of poverty.

"We are leaving behind the system that has in the past cost our country a heavy price in political and economic chaos," Erdogan said in an address late on Monday.