Hani Mohammad Saeed Al- Hassan was born in 1938 in the village of Ijzim in the Haifa Region from a prominent middle-class family. He was raised with two sisters and four brothers: Khaled, Ali, Masoud and Bilal. He was a leading member in the Fedayeen (freedom fighters) groups which  were formed by Sheikh Ezeddein Al Qassam. Afterwards, he became the orator of the Istiqlal mosque in Haifa.

 
As a result of the massacres which were committed by Zionist terror groups in 1948 with the aim of declaring the State of Israel, Al Hassan family left to Lebanon and then to Syria where he completed his secondary education. By the end of the 1950s, he went to Darmstadt in Germany to study engineering where he headed The General  Union of Palestinian Students and was known to be  one of the most active students in  promoting the Palestinian cause. Later on, he went to Russia where he had his PHD in media and communication. 

Al Hassan and his comrade (martyr Hayel Abdel Hamid) -Abu Al-Hol)    established training camps for an underground group which they have founded together (The pioneers of Returnees)  then they  joined  FATH movement after establishing contacts with Abu Jihad while in Algeria through Abdallah Al Ifranji  .

Hany Al Hassan acted as a FATH movement secretary General in West Germany until June 1967 when he became fully committed to the Movement. During the same year, he enrolled on a military course in China along with thirty other comrades of whom many became first class military and political leaders. Until 1969, he acted as the political commissioner and the Secretary General of FATH in Jordan.

In 1973, he was appointed as a deputy representative for FATH security and information apparatus which was chaired by the martyr Hayel Abdel Hameed.  

Hani Al Hassan assumed several high ranking positions in the PLO and was elected as a member in the Central Committee of FATH Movement during its 4th convention which was held in Damascus   on 5 May 1980   during which he was nominated as  its Foreign Relations Commissioner. 

Al Hassan developed broad relations with many Arab and foreign leaders. He used to be referred to as the man of difficult missions because of his proven negotiation skills with his opponents and counterparts.

In the aftermath of the Islamic Revolution in Iran which toppled the Shah, Al Hassan was assigned as the first Palestinian ambassador to Tehran and in the early eighties he was appointed as the Ambassador of Palestine to Jordan. 

He worked as a political and strategic advisor for Yasser Arafat while being in charge of the most crucial issues such as the relations with  various Lebanese counterparts during the PLO presence in Lebanon. This role could be compared to entering a minefield that may tear him apart at any moment if it explodes.

Given his proven competence in this respect, the late leader Yasser Arafat delegated to him more sensitive issues such as the internal restructuring of FATH Movement. 

Al Hassan  was able to restore the strategic parity for FATH movement after the strong blow it received  following its departure from Lebanon until the eruption of the first Intifada.  Since the inception of the movement, Al Hassan worked as the Foreign Affairs Commissioner for FATH until 2003.

During the  three months war of 1982 in Lebanon which, Al Hassan played a key role as a chief political  negotiator with the then American envoy  Philip Habeeb.  

During the 5th convention which was held in Tunis in August 1989, Al Hassan was re-elected   as a FATH Movement Central Committee member and   held its Foreign Relations portfolio while Abdullah Al Ifranji was nominated as his deputy.

In 1995 , Al Hassan  returned to Gaza  and despite his opposition to the Oslo Accords he was  appointed as  a political advisor for the Late president , Yasser Arafat  and became  the Minister of Interior for the  5th Palestinian cabinet (2002-2003)  for which he was given the responsibility of  restructuring the Palestinian security  apparatuses by merging them into three services.

During the year 2002(until 2007), the Late President , Yasser Arafat  appointed Al Hassan as the Head of the Mobilization and Recruitment Commission. He also acted as a political advisor for  President Mahmoud Abbas .

Due to his health condition , Al Hassan declined from attending the 6th Convention of FATH which was held in Bethlehem  in  2004 .

On the 6th of July 2012, Al Hassan passed away in Amman as a result of a brain stroke and was buried in Ramallah.

Within the keenness of President Abbas to honor the leaders and the early founders of the Palestinian Revolution and the PLO for their revolutionary history, he  awarded on 17 April 2014  Hani Al Hassan the  highest degree Star of Merit   Medal.