* Crimea was part of Russian Empire
* Soviet leader Khrushchev gave it to Ukraine in 1954
* Vote on Sunday will ask people if they want to join Russia
* Crimea is symbol of Russian identity, pride for Putin
By Andrew Osborn
SEVASTOPOL, Ukraine, March 13 (Reuters) - When President Vladimir Putin flew into the Ukrainian port of Sevastopol in Crimea last year, he made a pilgrimage to several sites associated with Russia's tumultuous history.
Clad in a sombre dark suit, he laid a wreath at an imposing Soviet World War Two memorial, visited a cathedral regarded as the cradle of Russian Christianity, and inspected Russia's Black Sea Fleet, recalling its Tsarist and Soviet-era glory.
His itinerary, meticulously choreographed by the Kremlin, goes some way to explaining why Putin, who has styled himself as a father of the nation-like figure overseeing Russia's rebirth as a great power, wants formal or informal control of Crimea.
For Putin, and for many Russians, Crimea has been a small part of Russia, heavy with historic and symbolic importance, trapped in a foreign land since the 1991 collapse of the USSR which saw it become part of an independent Ukraine.
With his third presidential term ending in 2018 and the possibility of a fourth that could see him stay in power until 2024, how Putin handles Crimea will shape his legacy.
The peninsula's importance to Putin and to Russia, from a historical, military and geopolitical point of view - and for how Russians see themselves - is hard to overstate.
As the home to one of Russia's four naval fleets, Crimea, opposite Turkey, is crucial to Putin's plans to project Russian power in the Black Sea and from there into the Mediterranean.
But for the ex-Soviet KGB officer, its importance runs much deeper. If Putin decides to annex Crimea, even some of his political opponents will laud him.
"If Putin gets Crimea back for Russia without bloodshed, he will be a great historical figure and there's nothing anyone can do about that," wrote Ksenia Sobchak, a prominent opposition activist and TV personality.
Ahead of a referendum on Sunday when this Ukrainian region votes to decide whether to come under Moscow's rule, thousands of masked Russian troops have fanned out across the peninsula. Ukrainian soldiers are virtual prisoners in their own bases, and Russian nationalists are waging a furious campaign to tip the vote their way.
For nationalists, dreams of a reconstituted Russian Empire always include Ukraine. Putin has been pushing plans to get some of the former Soviet republics together again on economic and political grounds. Russia formed a customs union with Kazakhstan and Belarus and Putin was keen to get Ukraine to join.
He also wanted to sign Ukraine up to a project called the Eurasian Union. Those plans now look holed. Absorbing Crimea, an event that nationalists believe will stoke separatist sentiment in east and southern Ukraine, would be a consolation prize.
'DRENCHED IN BLOOD'
The history of Crimea, purloined by Russia at the end of the eighteenth century by one of Putin's indirect predecessors, Empress Catherine the Great, neatly fits the narrative he and his advisers have tried to craft to give post-Soviet Russia a sense of worth and a new national identity.
It is a narrative that blends selected chapters of Tsarist-era and Soviet-era history, places a strong emphasis on military victories, and promotes the Russian Orthodox Church and its conservative values as a source of national moral guidance.
Crimea's blood-soaked role in two conflicts - in the Crimean War and World War Two - when it was a symbol of heroic but ultimately unsuccessful resistance against foreign powers, gives it an important role in Putin's new narrative.
"Every centimetre of Sevastopol is drenched in blood," Nikolai, a 35-year-old merchant sailor who said he would vote for Crimea to join Russia, told Reuters. "Many Russian soldiers died for this land. How can Russia let Ukraine ruin it?"
If Putin, who has yet to say how he would respond to a "yes" vote from Crimea, spurned the peninsula's overtures, Nikolai said it could hurt the Russian leader politically.
"Look at his rating now. It's high. But if he doesn't support Crimea becoming part of Russia people will turn away from him".
Crimea's status as the site where Vladimir the Great, a medieval ruler of the Kingdom of Kievan Rus, a precursor of modern-day Russia, accepted Christianity ensuring his people became Christians, lends it even further significance.
The peninsula has also long been at the centre of a historical grudge for Russian nationalists, who see Putin as their ally.
Part of the Russian Empire and then the Russian Soviet Socialist Republic for more than 170 years, Soviet leader Nikita Khrushchev, an ethnic Ukrainian, gifted Crimea to the Ukrainian Soviet Socialist Republic in 1954, on an apparent whim.
Many Russians see Sunday's referendum as a chance to right what they regard as a historical injustice.
"In years to come everyone will thank Putin for what he has done," Fyodor, a Sevastopol pensioner, said at a pro-Russian rally this week as a crowd behind him chanted "Russia Russia" and "Moscow is our capital".
"Putin will go down in history as the leader who resurrected the country. He will be remembered for supporting us and for uniting the Russian people."
Many Russians have fond memories of spending childhood holidays on Crimea's sandy beaches when the Soviet Union existed and the peninsular remains a popular vacation destination for Russians. If it became part of Russia, locals believe many more Russian holidaymakers would flock here.
Ethnic Russians already make up 58 percent of the peninsula's population of around 2 million and they say they are fed up with years of what they see as Ukrainian repression of their culture and language.
They welcome Putin's advances as those of a liberator.
"Putin is not a 100 dollar bill. Not everyone likes him. But we like Putin. So what?," said Julia, a 44-year-old ethnic Russian housewife helping blockade the Ukrainian's naval headquarters this week.
"If Barack Obama doesn't like Putin that's his problem," she said. "Obama is wagging his finger at Russia and saying Russia will have to pay the price. But why should it? It hasn't breached any international norms. Let's hope Obama has enough common sense not to unleash World War Three." (Editing by Richard Balmforth and Anna Willard)