The early sources are nearly in agreement that Hasan was poisoned by his wife, Ja'da bint al-Ash'at, at the instigation of Muawiyah and died in the year 670 CE. Madelung and Donaldson further relate other versions of this story, suggesting that Al-Hasan may have been poisoned by another wife, the daughter of Suhayl ibn ‘Amr, or perhaps by one of his servants, citing early historians such as Al-Waqidi and Al-Mada'ini. Madelung believes that the famous early Islamic historian al-Tabari suppressed this tale out of concern for the faith of the common people. Al-Hasan is said to have refused to name his suspect to Al-Husayn, for fear that the wrong person would be killed in revenge. He was 38 years old when he abdicated the reign to Mu‘awiyah, who was 58 years old at the time. This difference in age indicates a serious obstacle for Mu‘awiyah, who wanted to nominate his son Yazid as his heir-apparent. This was unlikely due to the terms on which Al-Hasan had abdicated to Mu‘awiyah; and considering the big difference in age, Mu‘awiyah would not have hoped that Al-Hasan would naturally die before him. Hence, Mu‘awiyah would naturally be suspected of having a hand in a killing that removed an obstacle to the succession of his son Yazid.