Profile: Mullah Fazlullah
Mullah Fazlullah, named as the new chief of the Pakistani Taliban, first came to prominence a decade ago with his fiery radio tirades against the Pakistani government, education and the polio vaccine.
The 39-year-old is a passionate ideologue, a cleric implacably opposed to any rapprochement with the Pakistani state. He has appeared in numerous militant videos wielding knives and guns as soldiers are slaughtered in the background.
Fazlullah claimed ultimate responsibility for ordering the shooting of schoolgirl Malala Yousafzai in 2012 and also said he was behind the killing of high-ranking army officer Maj-Gen Sanaullah Niazi in September.
A BBC correspondent, who met Fazlullah in 2009 in the Tirah Valley, was struck by his intensity and his commitment to bringing Sharia law to Pakistan. Although a fighter, he viewed himself primarily as a scholar.
"He has a forceful personality, very serious and radical. He was friendly, but absolutely committed to communicating his cause," our correspondent reports.
Tall and powerfully-built, Fazlullah was surrounded by his fighters when our correspondent met him and clearly enjoyed interacting with the media.
But he was also highly respected by previous Taliban leaders Baitullah and Hakimullah Mehsud.
Analysts view him as even more ruthless than his predecessor, Hakimullah. In a recent interview, he said his next target would be Pakistan's military chief Gen Ashfaq Kayani.
And on his accession, the Taliban said they would not hold back from targeting the army and the government.
This is the first time that the Pakistani Taliban have chosen a leader who does not come from the country's volatile tribal belt - or from the Mehsud or Wazir tribes.
Fazlullah is the head of the Swat faction of the Taliban and grew up in the mountainous Swat valley in what is now Khyber Pakhtunkhwa province.
It was there as a young man that he became close to Maulana Sufi Mohammed, the founder of the militant group Tehrek-i-Nehfaz Shariat-i-Mohammedi (TNSM) which aims to enforce Sharia law.
It was this militant faction that spearheaded the Taliban uprising under Fazlullah in northern Pakistan. They were effectively in control of the scenic Swat valley from 2007 and in early 2009 they gained de facto control of the entire Malakand division until an army offensive ejected them in the summer.
Reports say Fazlullah got his first taste of frontline combat experience in 2001 when his mentor Maulana Sufi Mohammad took him along with thousands of others to Afghanistan to fight the Americans. On his return, Fazlullah was arrested and jailed for 17 months.
After his release and as militancy was on the rise in Pakistan, Mullah Fazlullah began daily sermons on illegal FM frequencies. He installed several dozen FM transmitters and used them to spread his message throughout the region - possibly the first cleric to put religion on radio.
These were hate speeches directed against the Americans, the Pakistani state, female education, the polio vaccine and promulgating the militants' extreme interpretation of Sharia law. Charismatic and lyrical, these broadcasts saw him gain followers in the region and earned him the moniker Mullah Radio.
Some, after listening to his sermons, threw their television sets out because he described them as "un-Islamic". Many Swatis grew beards because of his lectures.
Afghan Taliban choice
His current whereabouts are unclear but many believe he is hiding along the Afghan-Pakistan border, perhaps in Afghanistan's Kunar province or in Nuristan.
If he is indeed in this area, it is the perfect hiding place as the isolated mountain hamlets and caves of the region have been used ever since the Afghan mujahideen fighters were battling Soviet troops in the 1980s.
Indeed correspondents say that Fazlullah is extremely close to the Afghan Taliban and was always their preferred choice as the Taliban leader in Pakistan.
Analysts say they respect his credentials as a scholar and a cleric and believe that he is the most likely to act in concert with their interests.
Although the Afghan and Pakistani Taliban have their own domestic agendas, analysts say the Taliban in Afghanistan believe Mullah Fazlullah was the most likely of all the Pakistani candidates to accept the supremacy of Mullah Omar, the spiritual founder of the Afghan Taliban.
Fazlullah has been falsely reported killed numerous times - and has been known to telephone the media to personally deny reports of his death.