The Pakistani Taliban have confirmed that their leader Baitullah Mehsud was killed in an American missile strike in August 2009. He was one of the most wanted militants in the country.
Baitullah Mehsud has a $5m US reward on his head
Baitullah Mehsud, as his name suggests, belonged to the Mehsud tribe in Pakistan's troubled South Waziristan region.
After 9/11 he grew in strength and stature and was said to command as many as 20,000 pro-Taliban militants. A majority belong to the Mehsud tribe.
South Waziristan is regarded as a safe haven for al-Qaeda and the Taliban, although recent advances by the Pakistani army in the neighbouring Swat valley mean that it is not now so secure.
Mehsud had a $5m US reward on his head.
His men are accused of playing a major role in advances made in recent years, especially in providing a sanctuary for fighters to operate in Afghanistan.
After a failed peace accord in February 2005, Baitullah Mehsud's militants waged a guerrilla war that virtually pushed the army out of South Waziristan. Afterwards he virtually ruled the area as his personal fiefdom.
From 2006 a wave of suicide bombings swept across Pakistan - credited by intelligence operatives to Mehsud's lieutenant, Qari Hussain, among others.
Mehsud came to worldwide attention in the aftermath of the 2007 Red Mosque siege in Islamabad - in which the security forces confronted and forcibly ejected militant students who were mostly loyal to him.
The violent end to the siege led to Mehsud further training his guns on the Pakistani authorities, ordering a string of bomb attacks, often involving suicide bombers, across the country.
The siege gave rise to a larger militant alliance across the tribal region called the Tehrik Taleban Pakistan (TTP), of which Mehsud became the leader.
The Pakistani government has also accused him of ordering former PM Benazir Bhutto's assassination in December 2007.
Mehsud denied he had anything to do with the attack.
Pakistani officials complained that the US failed to hit Mehsud with drone attacks despite them having supplied co-ordinates three times. The reason they gave was that Mehsud had been more focused against Pakistan in his militancy rather than fully directing his militants against Nato in Afghanistan.
Baitullah Mehsud had an aversion to publicity and photographs
But the dynamics in the region changed.
The Pakistani government said it had cowed the second largest TTP faction - in Bajaur tribal district.
A third - Maulana Fazlullah's in Swat - has been under heavy attack throughout much of 2009 by the army. It says that no militants no remain in the area.
Mehsud himself was reported to be part of a wider Waziristan-based alliance with groups led by Maulvi Nazeer in Wana and Hafiz Gul Bahadur in Miranshah.
Inter-factional rivalries were said to behind a deadly bomb attack on a restaurant in the town of Jandola in March 2009 that left at least 10 people dead.
Intelligence reports claim that Mehsud's force has a large number of foreigners.
Mehsud turned South Waziristan into his personal fiefdom
However, when the BBC's Syed Shoaib Hasan visited the Mehsuds in October 2007, no foreign fighters were visible.
The few journalists who met Mehsud spoke of his earnest desire to support his actions by his interpretation of Islamic ideals.
His emphasis was on jihad (holy war) against foreign occupying forces in Afghanistan and the establishment of an Islamic state.
Methods included the use of suicide bombers and cross-border attacks on international forces based there.
There was also his dislike of publicity in general, and to photography in particular.
It was an aversion he shared with supreme Taliban commander Mullah Omar, with whom he is said to have had a "good relationship".
Commander Mehsud said it was the duty of every Muslim to wage jihad against "the infidel forces of America and Britain".
Talking to the BBC in an exclusive interview earlier in 2007, he said the militants were determined to achieve their goal of freeing Afghanistan through jihad.
"Only jihad can bring peace to the world," he said.
The militant leader on several occasions openly admitted to crossing the border to fight foreign troops.