[ISTANBUL] Turkey on Sunday marked the 563rd anniversary of the Ottoman conquest of Istanbul with huge parties and a fireworks show in the former Byzantine imperial capital once known as Constantinople.
Around a million people were expected for a giant party in the city to mark its capture in 1453 by Ottoman Sultan Mehmet II, nicknamed "the Conqueror".
The Air Force aerobatics team was to perform a fly past prior to an evening fireworks display with Turkish President Recip Tayyip Erdogan and Prime Minister Binali Yildirim due at the festivities in the Yenikapi district in the European half of the city.
City authorities were also unveiling a 3D mapping of the city as it was in 1453 to mark an occasion advertised by the government for weeks.
Security was tight with Turkey on alert following several attacks in recent months attributed to Islamic State and Kurdish rebel groups.
A submarine, a frigate, five helicopters and 9,000 police - including a contingent of 40 elite snipers, plus dozens of sniffer dogs - were all on duty, according to the Anatolian news agency quoting city police chief Mustafa Caliskan.
Mr Erdogan's ruling Justice and Development Party (AKP) has since coming to power in 2002 sought to ramp up references to Turkey's Ottoman past, with critics lamenting apparent moves away from western influence towards "neo-Ottoman" imperialism.
At its height, the former empire stretched from the gates of Vienna to the Gulf of Aden.
A third bridge over the Bosphorus, currently under construction, has been named after Sultan Selim 1, under whose leadership the empire massively expanded in the mid 16th century and who some sources blame for the persecution of some 40,000 Alevis, a liberal Muslim minority.