The three most well-known martyrs among them were...
The three most well-known martyrs among them were: Muhammad bin Abdullah bin al-Hassan (al-Nafs al-Zakyyah), who was killed in 145 A.H., Hussein bin Ali bin al-Hassan (Martyr of Fakh), who was killed on the 8th of Dul-Hijjah, 169 A.H.
at the hands of the Abbassid ruler, Musa al-Hadi bin Abi-Ja'far al-Mansoor, near the well of Fakh in the vicinity of the holy city of Makkah, and Imam Musa bin Ja'far al-Khadhim (a.s.), the chief and Imam of Ahlul-Bait on the 25th of Rajab, 183 A.H, who was killed on the orders of the Abbassid ruler Haroon al-Rasheed. But these 33 victimized Shi'ites were only the leading men, famous and distinguished among the descendants of Abu-Talib.
As for the actual number of the victims, it is believed, based on historical accounts, that the number is at least many times larger. Imam al-Kadhim (a.s.) lived in the most critical and crucial time in the life of Ahlul- Bait (a.s.). The Abbassids hunted down the descendants of Imam Ali bin Abi-Talib (a.s.) and their followers, prosecuting them in every part of the Islamic state. Men recruited for this purpose were treated lavishly.
Their job was uprooting the Alawites, getting rid of their leaders because of their fear of the hostile activities of the Alawites and the love the common people held for them. In this eventful period of time revolutions erupted, followed by arrests and single or mass murders of the descendants of Imam Ali bin Abi-Talib (a.s.) and their followers. It was a dark age, men were caught and sentenced to death on the slightest suspicion.
The Abbassids monopolized power and thought little of peoples' dignity. Eventually, imprisonment, beating and killing became common practices. The Islamic state was turned into an empire governed by a hereditary dictatorship in which the Islamic state was divided into fieldoms. Governors ruled, abusing power, and acting according to their own wishes as long as they remained loyal to the central government and the Abbassid caliph.
The rulers sought men of this caliber who would remain faithful to them. The Abbassids were not concerned with establishing justice, implementing Islamic laws and introducing reforms. They only thought of their thrones and lusts. They busied themselves laying plans to eliminate their Entertainment, singing and base arts permeated the Muslim Society.