Their high-water mark came in 2009 when they advanced through the Swat Valley to within 80 miles of the capital Islamabad, before being back by a military offensive.
Since then they have struggled to maintain their coherence under pressure from drone strikes as well as internal disagreements about targeting civilians and entering peace talks.
The number of attacks outside the tribal areas has declined in the past year and analysts believe the movement is struggling after the death of Osama bin Laden, a key benefactor.
Hasan Askari Rizvi, an analyst based in Lahore, said: “They are not losing at the moment but they are certainly not winning either and so are considering their options, which is causing splits.” However, the TTP remains dangerous and has been blamed for a series of recent attacks in the north-western city of Peshawar.