How was yazid related to Iman Hussain?

Yazid ibn Muawiya was the Umayyad caliph and the son of Muawiya I, the founder of the Umayyad dynasty. Imam Hussain, the grandson of the Prophet Muhammad, was the son of Ali ibn Abi Talib and Fatimah, the Prophet's daughter. The relationship between Yazid and Imam Hussain was one of opposition; Hussain refused to pledge allegiance to Yazid's rule, which he viewed as unjust and corrupt, ultimately leading to the tragic events of the Battle of Karbala in 680 CE. This confrontation is a pivotal moment in Islamic history, particularly for Shia Muslims.