The origins of the Durand Line are one of the most under-researched aspects of the border dispute. Unanswered questions include: Was the 1893 border agreement signed under duress, as Afghan authorities and Pashtun nationalists hold? If not, why did Amir Abdur Rahman sign it? Did Ghaffar Khan, the founder of the Pashtun nationalist movement Khudai Khitmatgar, seek an independent Pashtunistan, or was he merely advocating autonomy? Did the 1947 referendum legitimising the inclusion in Pakistan of Pashtun territories represent the will of the majority of the local population, as Pakistani authorities hold? In this paper I will address these questions on the basis of archival sources, memoirs and government documents. I will first look at the context and terms of the 1893 agreement; then analyse the emergence of Pashtun irredentist claims and Afghan demands that territories annexed to India in 1893 be allowed to decide their destiny; and, finally, I will address Ghaffar Khan’s attitude in the run-up to partition and in its immediate aftermath.