The Mohmand Agency takes its name from the Mohmand Tribe, which inhabits the area.  The agency was established in 1951.  Earlier this area was under the administrative control of the Political Agent Khyber Agency, however in 1973, the headquarters of the Mohmand Agency was shifted to Ghalanai. Mohmand is an ancient tribe; a branch of Ghani Khel Afghan. The agency has an old history as its mountains were used for invasions from north into the Indian sub-continent. Archeological evidence suggests that this region was occupied by Aryans during 13th to 10th centuries BC. This area was a part of Gandhara civilization.
During the British Rule, this area was the hub of Mujahideen, who were struggling to get rid of British rulers and establish a free state.  In 1947,  at the time of creation  of Pakistan, from Subhan  Khwar to Yakka Ghund  Bazar, was the territory of Mohmand Agency  and  onward  from Yakka Ghund  Bazar the  area  was called free zone  (YAGHISTAN), where  there  was no writ of the Government. As Mohmand Tribe was the main enemy of the British forces, they made this area a part of District Charsadda. The Government separated the Taragzai Tribe from Mohmand Agency by force and included it in Charsadda.