Fourteen centuries ago, they murdered Muslim's leader, Hussain (peace be upon him) son of Ali bin Abitaleb (pbuh) and Fatimah (pbuh) in an area named
Karbala.
There were a mixed of truth and falsehood in that period of time. Muslims were divided into many groups; some of them followed Hussain, Muhammad's grandchild from his daughter Fatimah, though most of them remained silent out of fear toward Yazid's crimes who declared himself as caliph of the muslim region at the time, so that they'd flee his torturer agents.
Yazid forced Hussain to pledge alliance with him, but he refused and migrated from Madina to Mecca in that year. He left Madinah with his sisters, daughters, brothers, sons and the sons of Hassan. Later on he rose against the Yazid's rule, calling it not only oppressive, but also religiously misguided.
When Hussain was in Mecca, people revolted in Kufah against Yazid due to it's being the first establishment of a hereditary dynasty in Islam. The revolt in Kufah, the religious attitude and the crimes of the Umayyad, inspired people along with those who believed leadership of the Muslim community rightly belonged to descendant of Ali Bin Abi Taleb and Fatimah Bint Muhammad.
People of Kufa sent several letters to Hussain, urging Hussain to join them. At the time, Yazid had threatened to attack Mecca if he continues refusing. In order to avoid this sacrilege (killing a person in Mecca is prohibited in Islam), Hussain decided to emigrate from Medina to Kufah. He took along his wives, children, a few friends, companions and relatives.
On the way to Kufa, he was informed that people of Kufah have stopped their offer of him because of Yazid's threats, and Yazid has sent his army to fight with them.
Karbala was the place they faced each other. Imam Hussain knew his destiny as was prophesied by his grandfather, Prophet Muhammad. He previously informed his family and companions that they'd all be martyred, so anyone who might fear had the time to flee. At the end, there just remained 72 of his family and few companions whom couldn't be silent against injustice. In their idea they were winner either conqueror or martyr, since it was being murdered in the way of truth.
The battle of Karbala took place on Muharram 10. Hussain and his companions whom were 72 or so bravely fought against large army of 30,000 men under the command of Umar ibn Sa'ad, son of the founder of Kufah. Yazid's large army did a lot crimes. They acted so wild and cruel and didn't even show a pity to little children.
They blocked the river Forat against Hussain's army so that they wouldn't be able to reach water. They killed Imam Hussain's little baby who had just six months. They killed his brother Abbas while attempting to bring some water for thirsty children. They ripped Abbas's body into pieces and killed Hussain's young son and his nephews.
Hussain and all of his men were killed and beheaded. They beheaded Hussain in front of his sister's eyes and rode horses over his dead body and took his head with themselves to show to the people on the way.
The bodies were left for three days without burial. They fired tents, and tortured children and women. The survivors from Husain's family were taken as prisoners to Yazid.
This is one of the most disastrous events in the Islamic history and that's why Muslims and specially Shiites mourn
Ashoura every year, from the beginning of Muharram to the 10th. And this is the most important reason why Shiites don’t tolerate unjust rulers. And again that's why they defend their rights intensively and bravely against aggressors.
It was Hussain's school of thought which inspired the Iranian Islamic revolution about 30 years ago with the leadership of
Imam Khomeini.
