Husayn ibn Ali

Husayn ibn Ali (Arabic: حسين ابن علي, romanized: Ḥusayn ibn ʿAlī; 11 January 626 – 10 October 680 CE) was the second son of Ali and Fatima, a younger brother of Hasan and a grandson of the Islamic prophet Muhammad. He is the third Imam in Shia Islam, succeeding his brother Hasan and preceding his son Ali al-Sajjad. Husayn is a prominent member of the Ahl al-Bayt and Ahl al-Kisa, and a participant in the Event of the mubahala. Muhammad described Husayn and Hasan as the leaders of the youth of paradise. During the caliphate of Ali, Husayn accompanied his father in the military campaigns of the First Fitna. After the assassination of Ali, he obeyed his brother in recognizing the Hasan–Mu'awiya peace treaty, despite being suggested to do otherwise. Under the treaty, Hasan ceded the caliphate to Mu'awiya on the condition that the latter should rule in compliance with the Quran and the Sunnah, a council should appoint his successor (rather than appointing one himself), and Hasan's supporters would receive amnesty. During the nine-year period of Hasan's abdication and political retirement, Hasan and Husayn withdrew to Medina, seeking to remain removed from political involvement either in support of or opposition to Mu'awiya. After Hasan's death, the people of Kufa turned to Husayn and called for an uprising. Husayn instructed them to wait as long as Mu'awiya remained alive, in accordance with Hasan's peace treaty.

Prior to his death, Mu'awiya appointed his son Yazid as his successor, violating the treaty and making the caliphate hereditary. When Mu'awiya died in 680, Yazid demanded that Husayn pledge allegiance to him, but Husayn refused and questioned the legitimacy of his rule. As a consequence, Husayn left his hometown of Medina in 679 and took refuge in Mecca. While Husayn was in Mecca, the people of Kufa sent him numerous letters, inviting him to Kufa, asking him to become their Imam, and pledging their allegiance to him. Husayn first sent his cousin, Muslim ibn Aqil, to Kufa to assess the situation and the genuineness of their support. After receiving a favorable report from Muslim, Husayn accepted their invitation and traveled toward the city in response to their calls. On his way to Kufa with about 72 men, including his family members and close companions, Husayn's caravan was intercepted by a 1,000-strong army of the Umayyad Caliphate at some distance from Kufa. He was forced to head north and camp in the plain of Karbala on 2 October, where a larger Umayyad army of 4,000–30,000 arrived soon afterwards. Negotiations failed after the Umayyad governor Ubayd Allah ibn Ziyad refused to grant Husayn safe passage unless he submitted to his authority, a condition Husayn rejected. The Battle of Karbala ensued on 10 October, during which Husayn was brutally killed and beheaded along with most of his family members and companions, while the surviving members of his family were taken captive and brought first to Kufa and then to Damascus. The battle finalized the Shia–Sunni schism and was followed by the Second Fitna, during which the people of Kufa organized two campaigns to avenge the killing of Husayn; first by the Tawwabin, and the other by the revolutionary Mukhtar al-Thaqafi, who ruled over much of Iraq and parts of northwestern Iran for eighteen months and killed several figures responsible for Husayn's death.

Prior to the battle, Muslims were divided into two factions largely over the issue of succession to the Prophet: whether Ali was Muhammad's designated successor, or whether the prophet appointed no successor and had left the matter to the community. Karbala gave the Alids their own religious identity and played a significant role in the development and consolidation of what became Shia Islam. It holds a central place in Shia history, tradition, and theology, and has frequently been recounted in Islamic literature. The Battle of Karbala is one of the most tragic, pivotal, and defining moments in Islamic history. Husayn's suffering and martyrdom became a symbol of sacrifice in the struggle for right against wrong, and for justice and truth against injustice and falsehood. He is a universal, borderless, interfaith and meta-religion symbol. His martyrdom is commemorated during the annual ten-day mourning period of Muharram by millions of Muslims, especially Shia Muslims, culminating on the tenth day known as Ashura, the day when Husayn was killed. Every year on this day, over 35 million people in Karbala alone commemorate Husayn's death. Countless mourners around the world hold large public processions, organise religious gatherings, beat their chests and in some cases self-flagellate. Husayn and his companions are widely regarded as martyrs by all Muslims. The Imam Husayn Shrine in Karbala, Iraq, is a profoundly holy site in Shia Islam. Alongside his shrine stands the Shrine of Abbas, Husayn's half-brother, standard-bearer, and one of his principal supporters. The main event is the Arba'in pilgrimage, where up to 40 million visit the shrines. Most of the pilgrims travel on foot and come from all around Iraq and nearly 60 countries. While rooted in Shia Islam, the Arba'in pilgrimage has emerged as a symbol of interfaith engagement. It increasingly attracts participants from various religious backgrounds, including Christians, Jews, and non-Abrahamic faiths such as Hindus, Buddhists, Yazidis, and Zoroastrians, who all come to commemorate and mourn the martyrdom of Husayn. Arba'in is the largest annual public gathering on earth.