Hakimullah Mehsud is believed to be in his late 20s
Hakimullah Mehsud, the Pakistani Taliban leader, came to prominence in 2007 after a number of spectacular raids against Pakistan's army.
At that time he was one of several commanders under Taliban leader Baitullah Mehsud, who was killed in a US drone strike in early August 2009.
The BBC's Syed Shoaib Hasan recalls meeting Hakimullah - a nom de guerre he assumed replacing his birth name Zulfiqar - in South Waziristan in October 2007, just after he was appointed Baitullah's chief spokesman.
His audacious capture of 300 Pakistani soldiers had led to our correspondent travelling to meet the kidnapped troops.
Still only 28 at the time, Hakimullah Mehsud was clearly someone to be reckoned with, our correspondent recalls. Despite his pleasant demeanour and smile, danger radiated from him.
The kidnapping incident added to his prestige and Pakistan's government eventually released several high-profile militants in line with Taliban demands.
There have been several claims of his death made by US and Pakistani intelligence sources, none of which have been substantiated.
Hakimullah Mehsud's beginnings were hardly auspicious.
Born in the region of Kotkai near the town of Jandola in South Waziristan, Hakimullah Mehsud's only schooling was at a small village madrassa (religious school) in Hangu district.
One of the other students at the time was Baitullah Mehsud, but he dropped out.
Hakimullah Mehsud later joined his fellow clansman in jihad (holy war), initially acting as bodyguard and aide to the older militant.
Baitullah's consolidation of most of Pakistan's Taliban groups into a single entity provided growing opportunities for his talented young friend.
Hakimullah Mehsud was already famous within the Taliban for his skills in battle - his ability to handle a Kalashnikov and a Toyota pick-up were legendary.
"He is the best after Nek Mohammad," our correspondent's Taliban driver said during a hair-raising journey before the meeting in 2007.
Nek Mohammad was the founder of the Taliban movement in Pakistan.
He was killed in a suspected US drone attack in 2004 but not before he had made the Pakistani Taliban a force to be reckoned with.
The comparison with Hakimullah Mehsud sits well - both handsome young men with that extra aggressive instinct, our correspondent says.
Nek Mohammed was killed in a drone strike in 2004
But Hakimullah Mehsud also has a wild streak which borders on the reckless, he adds.
When they met in 2007, he took the BBC crew for a drive, handling the vehicle like a man possessed, manoeuvring around razor sharp bends at barely possible speeds.
He finished the demonstration by braking inches short of a several hundred-foot drop.
While the BBC crew sat in stunned silence, he just laughed chillingly and stuck the car in reverse to smoothly continue the journey, our correspondent says.
"I went to Karachi once when I was a small boy," he said when asked how and where he had travelled in Pakistan.
"But I used to go to Punjab quite often, and have been to Islamabad several times, though not recently."
Our correspondent met Hakimullah again in May 2008, at a now famous press conference organised by Baitullah Mehsud.
Baitullah Mehsud wanted to carve out a Taliban emirate in Pakistan
Hakimullah Mehsud had become a commander in his own right - masterminding the campaign against the Nato convoys in the Khyber tribal region and Peshawar.
He was later appointed Taliban commander for the regions of Khyber, Kurram and Orakzai.
In these areas, he has played a key role in a campaign of attrition against the Pakistani army.
In this respect he remains true to Baitullah Mehsud's ideology - carving out a Taliban emirate in Pakistan and taking on the army to defend it.
His appointment as leader was seen as confirmation that hardliners were in the ascendancy in the Pakistani Taliban.