The man who will decide both the fate of Islamic militant Osama Bin Laden, and of Afghanistan, is a reclusive figure whose friendship with the world's most wanted man has already brought his country almost complete isolation.

The Taleban spiritual leader Mohammed Omar and Bin Laden go back a long way, and Mullah Omar has never shown any sign that he is prepared to abandon his fellow resistance fighter from the Soviet occupation of Afghanistan of 1979 to 1989.

He has vigorously defended his friend against allegations that he masterminded last week's devastating attacks on the World Trade Center and the Pentagon, accusing the US of trying to cover up their own intelligence failures.

Bin Laden is believed to have at least partially financed the Taleban takeover of Afghanistan, from which Mullah Omar emerged as "commander of the faithful", a title with great resonance in Islamic history.

The ties go further. It is thought that Mullah Omar has taken Bin Laden's eldest daughter as a wife, and that Bin Laden may even have taken one of Mullah Omar's daughters as a fourth wife.

But the Taleban has always denied this.

No Western journalist has ever met Mullah Omar, who leaves virtually all contact with the outside world to his foreign minister, Wakil Ahmad Mutawakkil.

To many ordinary Afghans he is just a name, but those who have seen him say he is relatively young - in his early forties - and tall, with a black beard and a black turban.

His right eye was damaged by shrapnel when he was fighting Afghanistan's Soviet occupiers in the 1980s.

He rarely leaves the southern city of Kandahar where he lives in a large house that was reportedly built for him by Bin Laden, although he may be present in Kabul for a meeting of 1,000 senior Afghan Islamic clerics on Wednesday to discuss his friend's fate.

It is thought that the two speak daily by satellite telephone, and some reports suggest that they also meet for fishing trips.

Invisible fist

Under Mullah Omar's rule, a strict interpretation of Islamic law has been imposed on the 90% of Afghanistan which is ruled by the Taleban.

Women are strongly discouraged from leaving their homes, denied schooling and jobs and forced to fully cover themselves.

Women found guilty of adultery are stoned to death, homosexuals crushed under brick walls, thieves' hands are amputated and murderers publicly executed by victims' families.

Recent edicts from Mullah Omar have included the death sentence for anyone converting to another religion, as well as the infamous orders to destroy the country's ancient Buddha statues.

When the Taleban first arrived in Kabul in the mid-1990s, many ordinary Afghans welcomed them and Omar as heralding an end to the chaos caused by warring factions within the government.

A few months ago Mullah Omar told Pakistani journalist Rahimullah Yousifzei, the first journalist to interview him, that in his lifetime half of Afghanistan had already been destroyed.

He was ready to see the other half destroyed rather than give up Osama Bin Laden, he said.

It appears that this claim is now being put to the test.