Pakistan's tribal areas bordering Afghanistan are home to various groups that call themselves the Taliban. They emerged after 9/11, when Pakistan allied with the US and began launching raids in the tribal areas, which it had rarely entered before. Some groups evolved from ones that had been fighting India in Kashmir, but most were tribesmen who previously had not been active.
In late 2007, as many as 27 groups merged to form an umbrella Taliban movement, the Tehreek-e-Taliban, under the late guerrilla leader Baitullah Mehsud. But, over time, they became divided over whether to fight both the Pakistani and Afghan government or to focus solely on Afghanistan. Some groups even fought one another. Dozens of non-Taliban groups espouse similarly radical ideologies and fight in Afghanistan.
While some of these groups are based in the tribal areas, others are also in the so-called "settled regions," such as the Khyber-Pakhtunkhwa. A leading example is Lashkar-e-Taiba. It was banned after being accused of the attacks in Mumbai (formerly known as Bombay) in November 2008, but is still active in Afghanistan and Pakistan, according to US military officials. The US recently put a $10 million bounty on the apparent leader of the group. Many of these groups predate the Afghan or Pakistani Taliban and tend to remain independent of either group.