Alids of Tabaristan, Daylam and Gilan

Oppressive policies in Tabaristan, another dependency of Khorasan, result in the people of this province revolting against Tahirid governance and declaring their allegiance to the independent ruler Hasan ibn Zayd in 864.

Muhammad ibn Zayd is the younger brother of Hasan ibn Zayd, an Alid who had founded Zaydid rule over Tabaristan in 864.

Nothing is known of his early life.

Muhammad is mentioned during Hasan's rule as being captured by Ya'qub al-Saffar during the latter's 874 invasion, but released at Gurgan when Ya'qub withdrew in 876.

After a brief visit to Tabaristan to see his mother, he had returned to Gurgan as an assistant to Hasan's brother-in-law, Muhammad ibn Ibrahim.

The Zaydids had ben expelled from Gurgan by the Tahirid general Ishaq al-Sari in spring 877, but soon recovered it.

In 880, Muhammad also suppressed the rebellion of Rustam ibn Qarin, a member of the native Bavandid dynasty that rules the mountains of eastern Tabaristan and opposes the Zaydids.

He then suppressed a rebellion in Gurgan headed by another Alid, Hasan ibn Muhammad ibn Ja'far al-Aqiqi, and probably continued to govern the province in his brother's name until the latter's death on January 6, 884.

Power in Tabaristan is usurped upon Hasan's death by his brother-in-law, Abu'l-Husayn Ahmad ibn Muhammad, who proclaims himself as the legitimate emir due to Muhammad's absence in Gurgan.

Muhammad is prevented from returning to Tabaristan straight away by a mutiny by his Daylamite troops, and is able to regain control of Gurgan itself only through the aid of the former Tahirid general and now ruler of Khurasan, Rafi' ibn Harthama.

Muhammad is able to finally return in October 884 to Tabaristan, seize the capital Amol, and behead the usurper.

Muhammad assumes the same regnal name as his brother, al-Da‘ī ila‘l-Haqq ("He who summons to the Truth"), and is known as al-Da‘ī al-Saghīr ("the Younger Missionary") in contrast to Hasan (al-Da‘ī al-kabīr, "the Elder Missionary").

He is also found in some sources as al-Qa’im bi al-Haqq ("Upholder of the Truth").

Muhammad now attacks Rustam, who had supported the usurper Ahmad, and drives him from his domains to seek refuge at the Saffarid court.

 Saffarid mediation enables Rustam to return.

…Rayy in 889/890, where he establishes his headquarters.

During his stay in Tabaristan, Rafi had been joined by Ali ibn al-Layth, Amr's brother, who had initially been the favored candidate to succeed Ya'qub.

Ali's sons, al-Mu'addal and al-Layth, will later accompany Rafi in his attempt to regain control of Khurasan in 896.

Rafi invades and conquers the Zaydid domains of Gurgan and Tabaristan in 888/889, defeating the Zaydid ruler Muhammad ibn Zayd in battle at the Chalus River.

From Tabaristan, …

…Rafi marches to Qazvin, then …

The Saffarid army swears loyalty to Tahir ibn Muhammad ibn Amr, who soon afterwards effectively makes his brother Abu Yusuf Ya'qub his co-ruler, although the khutba will continue to be made in 'Amr's name until late 901.

Tahir and Ya'qub return to Sistan, reaching Zaranj in May of 900.

From the onset of his reign, Tahir and his brother are under the thumb of the Turkish slave commander Sebük-eri, who manages to destroy Tahir’s vizier and replace him with one more to his liking.

Amr ibn al-Layth, said to have started his career as a mule-driver and a mason, had later fought alongside his older brother and in 875 had become Governor of Herat.

When Ya'qub died in Fars in 879, Amr had managed to become the successor of the Saffarid throne over his brother Ali, who was the preferred choice of both Ya'qub and the army.

During his reign, he has faced several rebellions, such as that of Rafi ibn Harthama, who in 882 had taken over control of Khurasan and was a major threat to Amr's rule until he was finally killed in 896.

Now with Rafi dead, Amr is at zenith of his power, and has become so ambitious that he decides to conquer Transoxiana, which is Samanid territory.

The Transoxanian amir Ismail Samani scores a victory on May 28, 900, at Balkh over Amr Saffari.

The latter is captured and sent to the Abassid caliph in Baghdad.

The Samanid dynasty now rules over Khorasan as well as Transoxiana.

The Samanids also conquer the Zaydid emirate of Tabaristan a few months after their victory at Balkh.

The Samanid victory marks also the beginning of the dispersion of the local Shi'ites by the new Sunni power.