Al-Hasan Al-Basri bin Abi al-Hasan, the leader of the disciples of the Companions of the Prophet was, in fact, the son of Yasar the slave of Zayd ibn Thabit al-Ansari. His mother Umm ul-Hasan was a slave woman of Umm Salamah, the wife of the Prophet Muhammad (May Allah honour Him and grant Him Peace). So he was born in the house of the Prophet, and his father's master was one of the famous scribes who recorded Divine revelation for the unlettered Prophet.
Al-Hasan Al-Basri was one of the most renowned Tabi`een (the generation after the death of the Prophet) and prominent figures of his time. He was a jurist and a scholar. He was a pious and devout person. He was famous for his eloquence, inspiring speeches, wisdom, asceticism, and deep knowledge. He is the revered tabi`ee and the scholar of the people of Basrah, Abu Sa`eed Al-Hasan Ibn Abi Al-Hasan Ibn Yasaar Al-Basri.
Al-Hasan Al-Basri was born in Al-Madeenah in 21 AH/ 642 during the caliphate of the leader of the Believers, `Umar Ibn Al-Khattaab
Al-Hasan spent his early years with his family in Waadi Al-Qura near Al-Madeenah. Before he was fourteen years old, he managed to memorize the Glorious Quran. He also learnt reading, writing, and some mathematics. He heard many sayings of the Companions of the Prophet and he used to listen to the leader of the Believers, `Uthmaan Ibn `Affaan whenever he delivered the Friday sermon. Al-Hasan was fourteen years old at that time.
When he was fifteen years old, Al-Hasan moved to Basrah, Iraq in 36 A.H. He began learning jurisprudence, Hadeeth, and the Arabic language at the hands of a large number of the companions of the Prophet who were living in Basrah at that time.
Ubayy ibn Ka'b, Sa'd ibn 'Ubadah, 'Umar ibn al-Khattab, Thawban bin Bujdud, 'Ammar ibn Yasir, Abu Hurairah, 'Uthman bin Abi al-'Aas al-Thaqafi, Ma'qil bin Sinan al-Ashja'i, 'Uthman ibn 'Affaan, Ali ibn Abi Talib, Abu Musa al-Asha'ari, Abu Bakra al-Thaqafi, 'Imran bin Husain, Jundab bin 'Abdullah al-Bajli, ibn Umar, ibn Abbas, 'Abdullah bin 'Amr bin al-'Aas, Mu'awiya ibn Abu Sufyan, Ma'qil bin Yasar al-Mazni, Anas bin Malik, Jabir ibn 'Abdullah, Several Others (May Allah be please with them All).
Al-Hasan Al-Basri died on the first of Rajab, which was a Thursday night, 110 A.H., 728CE. His funeral was attended by a large number of people. Before his death, he stated that the following should be written down in his will:
This is what Al-Hasan Ibn Abi Al-Hasan believes: He testifies that none is worthy of being worshiped but Allaah and that Muhammad is the Messenger of Allaah. Whoever sincerely believes in this upon his death will enter Paradise."