In the name of God,  

I want to talk about one of the most important historical figures for Shiites, who has had the greatest impact on the lives of Shiites, and that is none other than Imam Hussein (peace be upon him), who is beloved by all Shiites around the world. To introduce him, I want to tell you who Imam Hussein was.  

Imam Hussein was the second son of Imam Ali (the cousin of the Prophet and the first Imam of Shiites) and Fatimah (the esteemed daughter of the Prophet), and he is the grandson of Prophet Muhammad. Imam Hussein is the third Imam of the Shiites and the brother of Imam Hassan, who was the first Imam after him. He belonged to the Banu Hashim family and the Quraysh tribe, and his sisters are Zainab and Umm Kulthum.

Hussein ibn Ali was born on the third of Sha'ban in Medina, and according to the most common account, his birth took place in the fourth year of the lunar calendar. However, some have stated that he was born in the third year of the lunar calendar.

When the news of his birth reached the Prophet Muhammad, he went to the house of Ali and Fatimah and asked to bring the child to him. Asma wrapped him in a white cloth and brought him to the Messenger of God. The Prophet then recited the adhan in his right ear and the iqamah in his left ear. On the seventh day after his blessed birth, the trustworthy angel of revelation, Gabriel, descended and said: "Peace be upon you, O Messenger of God. Name this newborn after the younger son of Aaron (Shabir), which is called Hussein in Arabic. For Ali is to you as Aaron was to Moses, except that you are the Seal of the Prophets."

Thus, the magnificent name "Hussein" was chosen by God for Fatimah's second son. On the seventh day of his birth, Fatimah Zahra, may God's peace be upon her, sacrificed a sheep for him, shaved his head, and gave silver in charity equal to the weight of his hair.

In historical reports from both Shiite and Sunni sources, it is mentioned that the Prophet cried at the time of his birth and foretold his martyrdom. It is narrated that Umm al-Fadl, the wife of Abbas ibn Abd al-Muttalib, had a dream in which a piece of the Prophet's body was placed in her lap. The Prophet interpreted her dream by saying that Fatimah would give birth to a son, and you would be his wet nurse. Therefore, when Hussein was born, Umm al-Fadl took on the role of his wet nurse. Some sources also mention that the mother of Abdullah ibn Yaqtar was a wet nurse for Imam Hussein, but it is said that Hussein did not nurse from either of them.

Imam Hussein spent six years of his life with the noble Prophet, and after the Prophet passed away, he lived for thirty years with his father. The Prophet had a deep affection for Imam Hassan and Imam Hussein. Anas ibn Malik narrates that when the Prophet was asked which of his family members he loved the most, he would often embrace Hassan and Hussein, smelling and kissing them.

After the martyrdom of Imam Ali, the leadership and Imamate of the Shiites were transferred to Hassan ibn Ali, the elder son of Amir al-Mu'minin, as per the command of the Messenger of God and the will of Amir al-Mu'minin. When Imam Hassan (peace be upon him) passed away, the Imamate and leadership of the Shiites were transferred to Imam Hussein, following the words of the Prophet, Amir al-Mu'minin, and the will of Hassan ibn Ali, and he was appointed by God to lead the community.

In most sources, it is mentioned that Hussein resembled the Prophet Muhammad and was considered the most similar person to him. It is said that Imam Hussein sometimes wore a fur garment or placed a fur turban on his head, and he would dye his hair and beard.

Imam Hussein was very kind and generous, known for his open-handedness. He would sit with the needy, accept their invitations, eat with them, and invite them to his home, never withholding anything he had from them. One day, a needy person asked him for help. While he was praying, Imam Hussein shortened his prayer and gave everything he had to the man.

Ibn Athir writes in his book "Asad al-Ghabah" that Hussein fasted frequently, prayed regularly, went on pilgrimage, and gave a lot of charity.

When the Imamate and leadership of the Shiites were transferred to Imam Hussein, he remained loyal to the peace treaty that his brother had made with Muawiya and did not oppose him. Muawiya, like the three caliphs before him, outwardly respected Hussein ibn Ali and regarded him highly, instructing his officials not to harm the grandson of the Messenger of God and to avoid disrespecting him.

After Muawiya's death, Yazid ascended to the Islamic throne and proclaimed himself Amir al-Mu'minin. He decided to force several prominent figures who had not accepted his caliphate, including Hussein ibn Ali, to pledge allegiance to him. However, Hussein refused to pledge allegiance and, along with his family and companions, left Medina for Mecca on the 28th of Rajab.

The Shiites of Kufa, having learned that their third Imam had not pledged allegiance, wrote letters to him and invited him to Kufa. Imam Hussein sent Muslim ibn Aqil to Kufa to report on the situation. After witnessing the people's warm reception and their pledges of allegiance, Muslim called for Imam Hussein to come to Kufa. In response, Hussein, along with his family and companions, set out from Mecca towards Kufa on the 8th of Dhul-Hijjah.

As Imam Hussein was heading towards Kufa in response to the invitation of the Kufans, he encountered an army led by Hur ibn Yazid al-Riyahi in an area called Dhul-Husam, and he was forced to change his course.

Imam Hussein and his companions arrived in Karbala on the second day of Muharram, and the following day, an army of four thousand people from Kufa, commanded by Umar ibn Sa'ad, entered Karbala.

On the evening of the 9th of Muharram, Umar Sa'ad's army prepared for battle, but Imam Hussein requested that night for prayer and supplication to God. On the night of Ashura, he spoke to his companions, took their pledges of allegiance, and allowed them to leave; however, they insisted on their loyalty and support for him.

On the morning of Ashura, the battle began, and by noon, many of Hussein's companions had been martyred. Then, his relatives, the first of whom was Ali Akbar, went into the battlefield, and one by one, they were also martyred. Finally, Hussein ibn Ali himself entered the battlefield and was martyred in the afternoon of the 10th of Muharram. Following this, the women and children, along with Imam Zain al-Abidin (peace be upon him), who was ill, were taken captive and sent to Kufa and then to Sham.

Although Imam Hussein and his companions were martyred, their sacrifice, along with that of 72 of his companions, created an epic that became immortal and will always remain in the heart of history.