Which country is both in Europe and Asia?

Turkey, split by the Bosphorus - about three per cent of its land is in Europe and the rest in Asia, with Istanbul straddling the water and being the only major city on two continents. Several other countries qualify depending on where the line is drawn, including Russia, Kazakhstan and Georgia, but Turkey is the one where the division runs through the middle of a city.

That strait is one of the most strategically valuable pieces of water in the world. It is the only route from the Black Sea to the Mediterranean, which means it is the outlet for Russian and Ukrainian grain and for the Russian Black Sea fleet. Its use is governed by the Montreux Convention of 1936, which gives Turkey control over warship transit - a treaty from before the Second World War that is still doing real work in current conflicts.

Istanbul has been the capital of the Roman, Byzantine and Ottoman empires and is the capital of none now, Ankara having been chosen in 1923 partly because it was defensible and inland and partly to mark a break with the imperial past. The city changed its name officially only in 1930; Constantinople and Istanbul had both been in use for centuries, and Istanbul appears to derive from a Greek phrase meaning simply to the city.