It is widely accepted that Vladimir the Great was baptised in Kherson, Crimea, an event in 988 that is considered to be the beginning of the Christianisation of Kievan Rus, a precursor state to Russia and Ukraine. Yet there are doubts concerning the event's relevancy to current events.

"Prince Vladimir was Kievan, not Muscovite, and this probably only underlines the right of Kiev and not Moscow to Crimea," Andrei Zubov, a Russian historian and political scientist, said. Historians argue over whether Vladimir was baptised in Vasilev, near Kiev, rather than Kherson, said Dr Zubov, who lost his post at the Moscow State Institute of International Relations in March, after he compared Mr Putin's takeover of Crimea to Nazi leader Adolf Hitler's annexation of Austria in 1938.

Mr Putin's interpretation of Crimean history adds a religious aspect to Russia's confrontation with the United States and the European Union after it annexed the peninsula from Ukraine in March. In his speech, Mr Putin called Crimea's March referendum, which backed breaking away from Ukraine, and its Parliament's decision to join Russia "absolutely legitimate", though thousands of Russian troops in unmarked uniforms had taken control of most of the territory earlier in the month and were in effect blocking all Ukrainian army and naval bases.

Since then, EU and US sanctions have helped tpush the Russian economy to the brink of recession as it wrestles with a 39 per cent slump in the value of the rouble against the dollar this year and a one-third decline in the oil price. Russia depends on oil and gas revenue for about half of its federal budget.

Mr Putin's speech has sparked religious as well as historical debate in Russia. From a religious viewpoint, Kiev was a much more important place for Russian Orthodox pilgrims than Crimea, Deacon Andrei Kuraev, a theologian and a popular Russian blogger, said. It was incorrect to compare Crimea with the Temple Mount, the world's holiest place for Jews, he said.