Abdullah Ocalan: A bridge between Kurds and Turks?
For decades, the islands on the Sea of Marmara outside Istanbul have been home to Turkey's most dangerous exiles and prisoners.
Ottoman princes were held there; Trotsky made the islands his home following his escape from Stalin's Russia; and a Turkish prime minister was executed there after a military coup in 1960.
The island of Imrali is now famous for one prisoner - a man Turkey often calls The Chief Terrorist.
His hair is white and he has lost weight. He spends his days reading academic works in his prison cell. He has an AM radio, and was recently given a television set.
For almost 14 years now, no-one apart from a handful of prison guards, politicians, lawyers and family members has seen him or heard his voice.
But Abdullah Ocalan remains the unquestioned leader of the Kurdish armed movement, the Kurdistan Workers' Party (PKK).
Message from a cell
Turkey's capture of Ocalan in Kenya in 1999 did not end his role in the conflict between the Turkish state and Kurdish rebels.
History shows that imprisonment can often increase a rebel leader's standing. Any doubts about Ocalan's continuing influence ended in November 2012.
He passed a message from his prison cell, ordering the ending of a hunger strike by hundreds of Kurdish activists.
His order was immediately obeyed.
This action may have forced the Turkish government into a profound decision: If it is to solve its 30-year-long conflict with the PKK, it may have to do so with the involvement of Ocalan himself.
Last December, reports emerged that the Turkish Prime Minister, Recep Tayyip Erdogan, had sent a senior intelligence official, Hakan Fidan, to Imrali island for talks with Ocalan.
Two Kurdish MPs were also allowed to visit the PKK leader.
These were rare new faces for Abdullah Ocalan. For years, the only person regularly allowed to visit the PKK leader on Imrali island has been his younger brother Mehmet, who works as a farmer in eastern Turkey.
"His amazing willpower is what keeps him alive," says Mehmet Ocalan from the family home in the village of Omerli.
A picture of Abdullah Ocalan playing in the snow hangs on the wall. "His conditions in prison are very tough."
The two men are usually allowed visits which last 45 minutes. The brothers are watched by prison guards.
"We talk about what's happening in the village, and about the family for about 15 minutes. Then for the next half an hour we talk about politics - about events in the region and around the world."
"Does Ocalan ever issue instructions to you to pass on to his followers?"
"Yes, he does. Sometimes he tells me things. I am a member of the Kurdish Peace and Democracy party, so he does.
"Abdullah Ocalan is a bridge between Kurds and Turks," Mehmet Ocalan insists. "If that bridge is broken, there may be serious divisions. I've said it before: He is a bridge. He is working for humanity to stop the bloodshed."
But others may disagree. Turkey, the US and the EU have designated the PKK as a terrorist organisation.
Its war with the Turkish state has cost around 40,000 lives. Among Turks, the hatred provoked by the PKK is deep.
But the desire to end the conflict may be even deeper.
"Today we are, once more - with ambition and patience - in an honest effort to end this violence and terror," the prime minister recently told his ruling AK party.
"Believe me we have one aim - which I repeat again - to stop the tears in all mothers' eyes."
But violence has marred the start of the peace process. In January, three Kurdish activists were killed in Paris, and buried here in Turkey.
Their deaths are unsolved. Mourners at the activists' funeral in Diyarbakir insisted that the peace process must go ahead.
The Turkish state wants the PKK to disarm. The Kurds want autonomy, the right to education and justice in their own language, and better conditions for Abdullah Ocalan.
His lawyers demand better access to their client. Firat Aydinkaya was last allowed to see Ocalan 18 months ago.
"The peace process is directly linked to Ocalan's conditions in prison," says Mr Aydinkaya, "If his conditions are improved, he will have a stronger hand and his peace messages will be more effective."
Turkey last heard Abdullah Ocalan's voice in 1999, during his trial on the island of Imrali. Many people in this country question his commitment to peace. But they do not doubt his influence.
The one man this country hates above all others is the same man it now approaches to try to end the Kurdish war.
Additional reporting by Zeynep Erdim