Who was the last of the Rightly Guided Caliphs, born in Medina, known for his clemency and eloquence, to whom the people of Iraq pledged allegiance for the caliphate after his father's assassination, and who died in the year 50 AH?

Al-Hasan ibn Ali ibn Abi Talib, may Allah be pleased with him, the grandson of the Prophet, may Allah's prayers and peace be upon him, was born in the middle of Ramadan in the third year of Hijra (some say fourth or fifth). Al-Hasan held the view that the matter should be left to Mu'awiya to prevent bloodshed. Abdullah ibn Ja'far agreed with him, and then Al-Hasan convinced Al-Husayn, may Allah be pleased with them both. Al-Hasan, may Allah be pleased with him, passed away in the year forty-nine, and some say in the year fifty or fifty-one, and he was buried in Al-Baqi'.