And then in 680, Mawawiya dies. Now, according to the treaty between Mawawiya and Hassan, it should have been some form of an election there. But Mawawiya says, or before his death, he makes Yazid the successor. And so Hussein, who is another son of Ali, Hassan's younger brother, and by this point, Hassan is dead, he says, hey, this is a breach of the treaty, and does not pledge his allegiance to Yazid. But there's a group in Kufa who say, hey, we will support you. And so Hussein goes to Kufa, but on the way there, and he's with his family, when Yazid catches wind of this, he sends an army to stop them. And Yazid's interest is essentially to eliminate Hussein and his family so that you don't have any other legitimate claimants to the caliphate.