Al-Layth and his brother al-Mu'addal had in 890 helped their father 'Ali bn al-Layth escape from imprisonment at the hands of the latter's uncle, the Saffarid ruler Amr ibn al-Layth.
The three of them had fled to Khurasan, where they had entered the services of the leading anti-Saffarid in that region, Rafi' b. Harthama.
After 'Ali died in 893, the brothers had continued to serve Rafi'.
After Rafi' was defeated and killed in 896 they had been captured by 'Amr, who however had treated them well.
Following 'Amr's capture by the Samanids in 900, the slave (ghulam) commander Sebük-eri had begun establishing ties with al-Layth, who had gone into hiding in Sistan.
As the son of 'Ali, who had originally been designated as the successor to Ya'qub ibn al-Layth al-Saffar, he is a possible contender for the amirate, and has gained supporters in the army.
Despite this, he had at first remained loyal to 'Amr's successor, Tahir ibn Muhammad.
He had participated in the abortive 900-901 campaign to recover Fars from the Abbasid Caliphate and another and more successful campaign that took place in around 904.
After the second Fars campaign, Tahir had returned to Zaranj, at which point both he and his brother Ya'qub had given themselves over to lives of pleasure and excesses.
Over the past few years, the two brothers have begun to lose the confidence of the people, and although the government bureaucracy has continued to function, the stability of the provinces has declined as rival factions opposed each other.
By 905, Sebük-eri had stopped forwarding taxes collected in Fars and Kerman to Zarang.
Tahir had responded by leading an army against Fars, but had soon been persuaded to abort the expedition and return to Sistan, having accomplished nothing.
In late 908, al-Layth arrives at Zaranj with a small army and occupies part of the city.
