Recep Tayyip Erdogan will be sworn into an executive Turkish presidency with sweeping new powers, vowing a "new era" for the country of 80 million people.
Erdogan has dominated Turkish politics for more than 15 years -- first as prime minister and since 2014 as president.
He was reelected on June 24 with 52.5 percent of the vote. The election followed a controversial 2017 referendum that transformed the government from a parliamentary system to a presidential one.
The changes will give Erdogan vast new powers, including over the judiciary and the ability to rule by decree.
Critics complained that the new system was turning Turkey into a "a one-man regime."
When he is sworn in, he will become both head of state and government, with the prime minister's post abolished and the parliament stripped of much of its power.
"Turkey is embarking on a new era with the presidential oath ceremony," Erdogan said on July 8.
He said there will be 22 presidents, 17 prime ministers, vice presidents, and parliament speakers from throughout the world for the swearing-in.
Russian Prime Minister Dmitry Medvedev is scheduled to attend.
Erdogan's ruling Justice and Development Party (AKP) won 42.5 percent of the vote, falling short of a parliamentary majority in the recent election, but it secured a total of 344 seats in the 600-seat chamber through its alliance with the far-right Nationalist Movement Party (MHP).
Erdogan's term is for five years, and there is a two-term limit on the office of the president for now, so he could stay in power until 2028.