Six years ago today, the Taliban assassinated the Afghan Northern Alliance leader Ahmad Shah Massoud. Massoud was one of the Mujahedeen leaders that the US backed against the Soviet Union in the 1980s. Massoud resisted the Pakistani-Taliban invasion of Afghanistan in the 1990s. He created the Northern Alliance, which proved to be a crucial US ally in 2001.
The Taliban assassinated Massoud on Sept 9th, 2001. The assassination and the 9/11 attacks marked the start of a major Taliban offensive against the Northern Alliance.