Khalaf's son Tahir is mentioned as having…

Khalaf's son Tahir is mentioned as having invaded Buyid Kerman in 1000, although he was ultimately unsuccessful in making any lasting gains.

Soon afterwards he, like 'his brother Amr before him, had rebelled against Khalaf.

The rebellion ends with Tahir's capture; he is imprisoned and dies not long after, in 1002.

With Tahir's death Khalaf is no longer left with any suitable heirs.

Khalaf's reign has grown increasingly unpopular over the years; his unpopularity has especially grown after Tahir's rebellion.

After Tahir dies, the commander of his army sends a message to Mahmud of Ghazna, stating that the people of Zaranj want him to become the ruler of Sistan.

Mahmud responds by sending an advance force to secure Sistan.

Khalaf resists, barricades himself in Taq and withstands a siege by the Ghaznavid force, so Mahmud decides to come personally in November 1002.

Mahmud's army is reinforced by the townspeople of Zaranj, eager to see the Saffarid defeated.

Khalaf is forced to surrender by December of 1002 and is sent to Farighunid Guzgan, where he will live until 1006 or 1007.