For over a thousand years Roman conquerors returning from the wars enjoyed the honor of triumph, a tumultuous parade. The conqueror rode in a triumphal chariot, the dazed prisoners walking in chains before him. And a slave stood behind the conqueror holding a golden crown and whispering in his ear a warning: that all glory is fleeting." - Patton
It had taken Alexander only six months to conquer Iran, but it took him nearly three years (from about 330 BCE–327 BCE) to subdue the area that is now Afghanistan.
Moving eastward from the area of Herat, the Macedonian leader encountered fierce resistance from the local tribes of Aria (West Afghanistan), Drangiana (now part of Afghanistan, Pakistan and Eastern Iran), Arachosia (South and Central Afghanistan) and Bactria (North and Central Afghanistan).
In a letter to his mother, Alexander described his encounters with the western and northern tribes (Afghans) thus: "I am involved in the land of a 'Leonine' (lion-like) and brave people, where every foot of the ground is like a wall of steel, confronting my soldier. You have brought only one son into the world, but everyone in this land can be called an Alexander.”
Local resistance and the difficult terrain made it difficult for Alexander's forces to subdue the region as many invaders have found the mountainous terrain of Afghanistan similar to a maze that often trapped outside invaders.