On the eighth of Rabi' Awwal, a painful occasion for the lovers of Ahl Al-Bayt (peace be upon them); the martyrdom anniversary of the eleventh Imam; Imam Al-Hassan Al-'Askari (peace be upon him). His life (peace be upon him) was rich in all meanings of Highness and asceticism, and he (peace be upon him) was known by his utmost fear of Allah the Almighty in his youth as he used to cry out of fear of God when he sees firewood, which is not surprising or strange from the people of the house of infallibility and purity (peace be upon them).
He (peace be upon him) had a high status in the eyes of his father Imam Ali Al-Hadi (peace be upon him) as he was the first to live with him and to know his right status, that is why he has hidden his son from people and only the closest friends could see him, to protect him for the survival of the descendants of the Imamate. And at the same time he used to show his status, as for example when Fahfaki has asked him about who will be the Imam after him, he (peace be upon him) answered: "Abu Mohammad, my son, is the soundest of the family of Mohammad (Allah's prayers be upon him and upon his holy Household) in excellence and the firmest of them in proof. He is the eldest of my (surviving) sons. He is the successor. To him, end, the bonds of leadership (Imamate) and our laws. Whatever you used to ask me about ask him. With him, you find what you are in need of."
After his reverend father, the Holy Imam (peace be upon him) undertook the task of leadership "Imamate'. His succession lasted about six years, and, in which, he practised different kinds of political and scholarly responsibilities as his divinely appointed forefathers accurately and efficiently did.
His epithets expressed his high and noble qualities. He was called: Al-Khalis (the pure), Al-Hadi (the guide), Az-Zakiy (pure, chaste, and righteous), At-Taqiy (pious), Al-Khass (peculiar), that Allah had distinguished him with virtues and with the responding to his supplications. As-Samit (silent), that he was silent and he spoke just wisdom, knowledge, and the mention of Allah. As-Siraj (lamp), that he was as a lamp lighting the way and guiding the deviant to righteousness. And the most famous: Al-'Askari (military); he was called so because of the country (Samarra’) he lived in which was a military camp. In addition to many other epithets expressing his piety and virtues.
Imam Abu Mohammad Al-Hassan Al-'Askari (peace be upon him) was poisoned by the caliph, Mu'tamad, and, thus, suffered severely and was martyred on 8th of the month of Rabi' Awwal in the year 260 (A.H.). The reason that caused the Abbasids to be more envious against the high position of the Holy Imam (peace be upon him), among the Ummah, was their being afraid of his son, the Awaited Imam Mahdi (peace be upon him). They knew that Imam would be the son of Imam Al-‘Askari (peace be upon him) whom he referred to in one of his letters: "They thought that they could kill me in order to cut off my offspring, but Allah denied their sayings and praise be to Allah." The anger of the caliph, Mu'tamid, increased more when he saw that the whole Ummah glorified, and showed great respect and superiority to the Holy Imam (peace be upon him); and the Shias more than the Abbasids. On the other side, the caliph, Mu'tamid was greatly hated by the whole Ummah. Therefore, he decided to annihilate the Holy Imam (peace be upon him) and assassinate him.
At the time of his death, he was twenty-eight years old. He was buried in the house in which his father was buried in Samarra'. He left behind his son - Living Holy Awaited Saviour Imam Mohammad Al-Mahdi (peace be upon him) the one who is awaited to bring about the heavenly rule of truth in the whole world.