The dynasty's founder was Ya'qub bin Laith as-Saffar, who was born in 840 in a small town called Karnin (Qarnin), which was located east of Zaranj and west of Bost, in what is now Afghanistan.

He seized control of the Sistan region and began conquering most of Iran and Afghanistan, as well as parts of Pakistan, Tajikistan and Uzbekistan.

They first invaded the areas south of the Hindu Kush, and then overthrew the Tahirid dynasty, annexing Khorasan in 873.

By the time of Ya'qub's death, he had conquered the Kabul Valley, Sindh, Tocharistan, Makran (Balochistan), Kerman, Fars, Khorasan, and nearly reached Baghdad but then suffered a defeat by the Abbasids.

[5] From his capital Zaranj he moved east into al-Rukhkhadj (Arachosia), Zamindawar and ultimately Kabul, vanquishing the Zunbils and the Hindu Shahis by 865.

[15] The Saffarids then seized Khuzestan (southwestern Iran) and parts of southern Iraq, and in 876 came close to overthrowing the Abbasids, whose army was able to turn them back only within a few days' march from Baghdad.

[16] These incursions, however, forced the Abbasid caliphate to recognize Ya'qub as governor of Sistan, Fars and Kerman, and Saffarids were even offered key posts in Baghdad.

[14] In 1002, Mahmud of Ghazni invaded Sistan, dethroned Khalaf I and finally ended the Saffarid dynasty.

[18] Since Kharijism prospered in Sistan longer than anywhere else in eastern Iran, it was believed the Saffarids held Kharijite sympathies.