President Recep Tayyip Erdogan is to be sworn in for his second term as head of state on Monday, taking on greater powers than any Turkish leader for decades under a new system condemned by opponents as a one man regime.
Erdogan, who has transformed Turkey in 15 years of rule by allowing Islam a greater role in public life and boosting its international stature, will take his oath almost two years after defeating a bloody attempted coup.
The inauguration in parliament after Erdogan's June election victory will be followed by a lavish ceremony at his palace attended by dozens of world leaders marking the transition to the new executive presidency system.
Erdogan will face immediate and major challenges posed by an imbalanced if fast-growing economy and foreign policy tensions between the West and Turkey, a NATO member.
He has also pledged to end the state of emergency that has been in place since the failed July 2016 coup and which has seen the biggest purge in the history of modern Turkey.
In what appeared to be the final emergency decree issued just one day before the inauguration, 18,632 public sector employees were ordered dismissed including thousands of soldiers and police officers.
After the inauguration,
, visiting northern Cyprus and Azerbaijan followed by more challenging encounters at a NATO summit in Brussels where he will meet US counterpart Donald Trump and other leaders.
The new system was agreed in a bitterly fought 2017 referendum narrowly won by the 'Yes' camp. The issue still polarises Turkey.
"A partisan one-man regime starts officially today," said the opposition Cumhuriyet newspaper.
Its commentator Asli Aydintasbas wrote: "I don't think it would be an exaggeration to say that we entered a 'second republic' era," after the republic set up by Turkey's secular founder Mustafa Kemal Ataturk.
But the pro-government daily Yeni Safak wrote under the headline "historic day": "One page is closing in Turkish history and a new page is opening."
The president will sit at the top of a vertical power structure marked by a slimmed-down government with 16 ministries instead of 26 and multiple bodies reporting to him.
In one of the most significant changes, the EU affairs ministry, set up in 2011 to oversee Turkey's faltering bid to join the bloc, will be subsumed into the foreign ministry.
Prime Minister Binali Yildirim will on Monday go down in history as the 27th and final holder of the post in Turkey. He is expected to become speaker of the new parliament.
Leader of multi-polar world
The grand transition ceremony, to be attended by some 10,000 guests and marked by dozens of gun salutes, has been overshadowed by a deadly train derailment in northwest Turkey on Sunday that left 24 dead.
Those attending will include Ankara's top allies from Africa, the Middle East and the former Soviet Union but relatively few European figures.
Russian Prime Minister Dmitry Medvedev will attend, in a new sign of the warm ties between Ankara and Moscow, as will Venezuelan President Nicolas Maduro, regarded with disdain by Washington but an ally of Erdogan.
Tweeting a video apparently showing himself driving to the airport, Maduro hailed Erdogan as a "friend of Venezuela and leader of the new multi-polar world."
Sudan's President Omar al-Bashir is on the guest list as is Emir Sheikh Tamim bin Hamad Al-Thani of Qatar, Turkey's closest ally in the Middle East. The only EU leaders are set to be Bulgarian President Rumen Radev and Hungary's strongman Prime Minister Viktor Orban.
The new cabinet, due to be announced at 1830 GMT, is expected to have a different look, with pro-government Hurriyet daily columnist Abdulkadir Selvi saying that it was set to "surprise" with figures from outside the ruling Justice and Development Party (AKP).
Current Foreign Minister Mevlut Cavusoglu could in theory continue in his job but reports have said Erdogan may choose his spokesman, Ibrahim Kalin, or even spy chief Hakan Fidan to succeed him.
The markets will keep a close eye on economic appointments, keen to see a steady hand at the helm in a fast-growing economy dogged by double-digit inflation and a widening current account deficit.
Erdogan, who first came to power as premier in 2003, won an outright victory in June 24 polls, defeating his closest rival, Muharrem Ince of the main opposition Republican People's Party (CHP) which is now locked in internal battles over its future direction.
The AKP failed to win a majority in legislative elections and will need support from its allies in the right-wing Nationalist Movement Party (MHP) who could push it into more hardline policies.