Ahmed Shah, founder of the Afghan monarchy, born about 1724, died in 1773. Ahmed was the son of Sammaun Khan, the amir of the great tribe of the Abdallis and of the family of the Suddosis. At his father's death he and his brother Zulfucar fell into the power of Hussein Shah, the head of the tribe of the Ghiljis, who was then master of Candahar. At this period Afghanistan was subject to Persia. On the invasion of India by Nadir Shah, the two young princes were rescued from the hands of Hussein and sent into Persia. Ahmed's brother died in captivity, but he himself was taken into the service of the usurper, and promoted to the command of a body of horse. When Nadir was assassinated in 1747, Ahmed and his tribe attempted to avenge his death. But finding the Persian army too powerful, he retreated into the fastnesses of his native country, changed the name of his tribe from Abdalli to Durrani, which they still retain, raised the standard of independence, proclaimed himself shah, and was soon joined by the amirs and their several tribes.

His first act was to seize a convoy of treasure coming from India to Persia, and to possess himself of the famed Koh-i-noor diamond (now in possession of the British crown), which had fallen into the hands of Nadir Shah. Aware that his power depended on finding occupation for his turbulent subjects, he led them at once to conquest, and rapidly subdued the provinces surrounding his realm and part of the kingdom of Persia. He then directed his arms to India, overran the Punjaub and Cashmere (1752), and penetrated (1756-'7) as far as Delhi, the capital of the Mogul emperor Alam-ghir, whither that monarch, jealous of his vizier's excessive power, is said to have earnestly summoned him. The crafty vizier, Ghazy-ed-Deen, propitiated Ahmed, and, professing entire subservience to his views, induced the Afghan monarch to leave him in possession of his ill-gotten power as a check upon his sovereign. Ahmed entered Delhi in triumph, sacked it, and invested his son, Timour Shah, with the government of the Punjaub and of Sirhind. In retiring from Delhi, he left a lieutenant to hold both the vizier and the Great Mogul in check.

No sooner was the restraint of his presence removed than the minister rose on the Afghan commander, drove him out of Delhi, and assassinated the emperor, placing a prince of the blood royal on the throne. The Mahratta chieftains now saw their opportunity for expelling the Mohammedan rulers altogether, and establishing Hindoo supremacy. Ahmed Shah brought a powerful army into the field (1759). More than a year was spent in manoeuvres and skirmishes, till the Mahrattas took up an intrenched position at Paniput, when Ahmed cut off their supplies, and forced them to an engagement, Jan. 6, 1761, in which the Mahrattas sustained a decisive defeat. The shah, however, saw the impossibility of maintaining the Mogul empire, and left it to its fate. The Sikh chieftains in the Punjaub revolted against him, and he crossed the Indus for the sixth time in 1762, and coerced them to a temporary obedience, which they finally threw off after a seventh expedition of Ahmed in 1763-'4, made unsuccessful by the desertion of part of his army.

He was succeeded by his son Timour.