Imam Hussein (A.S) revived Islam and Islamic Ummah

It is narrated from Imam Hussein (A.S) who said: When the Islamic Ummah (nation) is struck with a ruler such as Yazid, must say farewell (goodbye) to Islam [1]. In a letter to some leaders in Basrah (a large city in Iraq), Imam Hussein (A.S) explained the aim of uprising against Yazid’s rule: I call upon you (invite you) to the book (the Qur’an) of Allah (SWT), and the traditions of God’s Prophet (PBUH), because this group (Yazid and his accomplices) has destroyed the traditions of the Prophet (PBUH) [2]. In his will, Imam Hussein (A.S) wrote: I have not come out of Medina out of stubbornness, or for pleasure, or corruption, but I have risen for revival of my grandfather’s Ummah, I want to enjoin good and forbid wrong [3].
Source: shafaqna.com