Hussain is the son of Sayyidina Ali (R.A) and the grandson of Prophet Muhammad who took a stand against Yazid’s evil rule. Whilst Yazid was feared and hated for his ruthlessness, Hussain was loved and respected by society. Yazid realised this, and understood that if he could convince Hussain to support him, the people would too.
Hussain had a choice. To support the tyrant and live a comfortable life full of luxury, or to refuse and likely be killed for his decision. What should he do? What would you or I do? For Hussain he could not live his life as a supporter of tyranny, and the choice for him was simple. Hussain refused. He said “I only desire to spread good values and prevent evil”
The twins of Ali and Fatima the prophets daughter were the only descendants of the Prophet after his death as the Prophet only left Fatima behind after his death.