Hazrat Hassan (pbuh), one of the People of the Book, was the grandson of our Prophet (saas). He was the son of Hazrat Ali (pbuh) and the Prophet’s (saas) daughter Hazrat Fadime (pbuh) and was born in Medina on the third year of the hegira. The Prophet Muhammed (saas) read the call to prayer (adhan) into his ear and gave him the name “Hassan.”

Hazrat Hassan (saas) was one of the young people who swore allegiance to Rasulullah (saas) while still a child. He was brought up with his immaculate education. He is the subject of much praise from Rasulullah (saas) in many hadiths.

When he was eight, he lost first his grandfather, the Prophet Muhammed (saas), and then his mother, Hazrat Fatima (pbuh). He was then raised by his father, Hazrat Ali (pbuh). Hazrat Hassan (pbuh) had an attractive, white face, and resembled our Prophet (saas) more than anyone else.

Hazrat Hassan (pbuh) was filled with the love of Allah, gentle, dignified, peace-loving, compassionate, patient and virtuous. He spent his possessions on Allah’s path and gave away much in alms. Hazrat Hassan (pbuh) went on the hajj, on foot, 25 times. He had 15 sons and eight daughters. All his wives loved Hazrat Hassan (pbuh) very much. Together with Hazrat Hussein (pbuh), Hazrat Hassan (pbuh) is one of the two holy figures through whom the line of our Prophet (saas) has come down to the present day.

Our Prophet’s (saas) love and affection for Hazrat Hassan (pbuh)

Our Prophet (saas) loved Hazrat Hassan (pbuh) very much and treated him with great affection. Several companions described how our prophet (saas) loved his grandchildren and took an interest in and played with them.

Al-Barra (pbuh): "I saw the Prophet (saas) with Hassan on his shoulder." (Imam Muhammed Bin Muhammed bin Suleyman er-Rudani, Great Hadith Collection, Jam'ul-fawaid min Jami al-usul ve Majma az-Zawaid, Vol. 5, İz Press, p. 13 )

ADNAN OKTAR: They traveled around on their grandfather’s shoulders, our Prophet (saas). One on the right shoulder, one on the left. Our Prophet (saas) used to carry them round in the garden and such places, or when going to the mosque. That was what they delighted in most, clinging to their grandfather. They were both truly very cute, masha’Allah. (11 June 2011)

Rasulullah (saas) loved Hazrat Hassan (pbuh) very much. He would joke with him, place him on his lap, kiss him and allow him to play with his blessed hair. Usama, son of Hazrat Zaid (pbuh) said this of our Prophet (saas)  :

"Rasulullah would put me on one knee and his grandson Hassan on the other; then he would embrace us both and pray, “O Lord, have mercy on them. Because I am most compassionate toward them.” (Kutub- al-Sitte, Translation and Commentary, Prof. Dr. Ibrahim Canan, Vol. 2, Akçağ Press, Ankara, p.508)

As a young child, Hazrat Hassan (pbuh) would come to our Prophet (saas) when he was praying and climb on his back and neck as he prostrated himself. Because of his love and compassion for Hazrat Hassan (pbuh), Rasulullah (saas) would get up very slowly in order that he should not fall off.  Rasulullah (saas) would often call his two grandsons, Hassan and Hussein, whom he described as “the two pillars of the world,” to him and embrace them to him.

Abû Ayyûb Ansârî (pbuh) relates: “One day, I came into the presence of Rasulullah (saas). Hassan and Hussein were playing in front of him. ‘O Rasulullah, you must love them very much,’ I said.” “HOW COULD I NOT LOVE THEM? THEY ARE MY TWO PILLARS IN THIS WORLD, WHOM I KISS AND SMELL!” he said. (Bukhari, Fedailiu's-Sahabe 22, Edeb 18; Tirmidhi, Menakib 30)

“Whoever loses the sun must turn to the moon. If he loses that, he must turn to the stars.” When the people of Qiram asked for an explanation of this hadith, Rasulullah (saas) said, “I AM THE SUN. THE MOON IS ALI. Fadime is a star. THE TWO STARS NEAR THE NORTH POLE ARE HASSAN AND HUSSEIN.” (TamOSE  İlmihâl Se’âdet-i Ebediyye sh-1011)

"Whoever loves Hassan and Hussein loves me, but whoever hates them hates me. " (Ahmed b. Hanbel, Musnad, II, 288);

The caliphate of Hazrat Hassan (pbuh)

With the martyrdom of Hazrat Hassan’s (pbuh) father, Hazrat Ali (pbuh), he became caliph in 661 AD. Forty thousand people swore allegiance to him. In the seventh month of his caliphate, as his and Muawiyah’s armies were making preparations for battle near Baghdad, Hazrat Hassan (pbuh) relinquished the caliphate in favor of Muawiyah. Because of this agreement in 661, that year was known as “Amu’l Camaa,” the year of unity, in the history of Islam. At the same time, this also pointed to a miracle of our Prophet’s (saas).  Because when Hazrat Hassan (pbuh) was very young, Rasulullah (saas) pointed to him and said, “This son of mine is a Sayyid. Almighty Allah will reconcile two sides through him.”  No Muslim blood was spilled due to Hazrat Hassan’s (pbuh) relinquishing the caliphate, and peace and tranquility were established.  In this way, Rasulullah’s (saas) words about Hazrat Hassan (pbuh) came true.

Hazrat Mahdi (pbuh) is descended from the line of Hazrat Hassan (pbuh)

In the hadiths, our Prophet (saas) describes “distinctive and distinguishing”  features of Hazrat Mahdi (pbuh) so that Muslims can recognize him. One of these is that “Hazrat Mahdi (pbuh) will be descended from  the line of Hazrat Hassan (pbuh).”

“HAZRAT MAHDI IS ONE OF THE CHILDREN OF HAZRAT FADIME AND DESCENDED FROM THE LINE OF HASSAN.“(Abu Dawud, Hazrat Mahdi, 1)

Tamman relates in his work the Fevaid, and Ibn Asaqir relates from Abdullah b. Amr that he said : ONE WHO IS A CHILD OF HASSAN (HAZRAT MAHDI) will appear from the East, and even if the mountains oppose him he will overcome them and make paths for himself in the mountains.  (Ali Bin Hüsamettin al Muttaki, Hadiths from Jalaladdin Suyuti's Classification – Portents of Hazrat Mahdi of the End Times, p. 22)
Rasulullah (saas) gave Hazrat Mahdi (pbuh) and Hazrat Hassan (pbuh) the glad tidings of paradise 

Hakim, Ibni Majah and Abu Naim related from Hazrat Enes; I heard Rasulullah (saas) say: Seven people from among the sons of Abdulmuttalip are the lords of paradise. Me, Hamza, Ali, Jaffar, HASSAN, Hussein and HAZRAT MAHDI.  (Ali Bin Hüsamettin al Muttaki, Hadiths from Jalaladdin Suyuti's Classification – Portents of Hazrat Mahdi of the End Times, Kahraman Press, p. 19)
What Hazrat Ali (pbuh) said about Hazrat Hassan (pbuh), Hazrat Hussein (pbuh) and his own martyrdom

Hazrat Hassan (pbuh) was exposed to various forms of persecution during the 10-year period of the Imams. He was not even safe in his own home and he was eventually poisoned and martyred in the 50^th year of the hegira. 

ADNAN OKTAR: Look, what does my forebear say? My beloved Hazrat Ali (pbuh) said: “I swear to Allah that I and my two sons Hassan and Hussein will be martyred.” He swore to Allah while he was still alive. Our Prophet (saas) said, you and you and you, the three of you will be martyred. He swore that since it came through revelation. Look, Hazrat Ali (pbuh) said: “Thanks be to Allah, I swear to Allah I and these two sons of mine will be martyred.” “And he will send one of my descendants,” (Hazrat Mahdi) he says. “He will seek our blood and take vengeance for us.” How? Through establishing a global reign. The line of the Prophet (saas) had come to an end, hadn’t it? But he will appear, and the line of the Prophet (saas) will establish a global reign, insha’Allah. Millions of sayyid will rise up, in the spiritual sense, insha’Allah. He says he will seek our blood. The blood of Hazrat Hassan (pbuh) and Hazrat Hussein (pbuh) and Hazrat Ali (pbuh) will be smeared on Hazrat Mahdi’s (pbuh) brow. He will take revenge for them. That is his global reign, the elimination of disbelief. Of course, the blood is rubbed on his brow in three lines, insha’Allah, insha’Allah.