Al-Qasim ibn Hasan (Arabic: القاسم بن الحسن) ( Sha’aban 7, 47 AH /September 19, 668 CE – Muharram 10, 61 AH /October 10, 680 CE), was the son of the Imām, Hasan ibn Ali from his wife Umm Farwa, and grandson of Ali ibn Abi Talib and Fatimah (PBUT). He took part in the battle of Karbala, in which he was martyred.
He was born three years before the martyrdom of his father. Qasim, like his cousins, Aun and Muhammad, who were his aunt Zaynab’s sons, learnt fencing from his uncle Abbas and his cousin Ali Akbar.
When Hasan’s brother Imam Husayn prepared to leave Medina in 680, Qasim’s mother Umm Farwa asked Husayn to take her and Al-Qasim with him, he agreed.
Al-Qasim was married to Husayn ibn Ali’s eldest daughter, Sakinah (Fatima al-Kubra) bint Husayn, who was 11 at the time. It is said that Husayn made a promise to his brother Hasan that he will marry his daughter to his son. Therefore, knowing that he was going to die, he arranged the marriage on night of seventh of Muharram, three days before the day of Ashura to keep his promise. It is quoted in Madinat-ul-Ma’ajiz and Wafiyat Al-Aaimmah,
“My son Qasim, a day will come when my brother Husayn will be facing an enemy army of tens of thousands. That will be the day when Islam will need to be saved by sacrifice. You must represent me on that day.” ”
Al-Qasim read the letter and rushed to his uncle and gave him the letter. After reading the letter Hussain said,
“ “O my brother’s son, how can I stop you from doing what your father wanted you to do? In the Name of Allah, go! Allah be with you!” ”
When he got up on the horse he looked like a shining moon. Al-Qasim was a very handsome boy.
When he went to the battle field, he fought with all of his strength and killed a lot of the enemies. But, he was only a boy and was thirsty for three days due the blockage of the river by Yazid’s army. A man came from behind and hit Al-Qasim with his sword to which he fell and cried aloud, “O, dear uncle, peace be upon you” Husayn rode out upon hearing this. The soldiers tried to stop him, when finally he came to where Al-Qasim had fallen. He saw Al-Qasim’s body trampled to pieces by the horses of the soldiers who had tried to stop them from reaching to their nephew.
When the time came for Imam Husayn to take his nephew’s body back to the tents he took off his aba, spread it on the ground and picked the pieces of the body up as one would collect flowers from a garden.