Walid Ahmed Nimer Nassr Al-Hasan (Abu Ali Iyad) was born on the 12th of January 1935, in Qalqiliya. 
Al-Hasan he completed his secondary school education in Qalqiliya in 1953, and worked for a short time as a teacher in Qalqiliya and ‘Azzun. In 1954, he took a training course in teacher preparation in Ba’qubah, Iraq, and from 1954 and 1962, worked as a teacher in the Kingdom of Saudi Arabia. During his career, however, Abu Ali Iyad was not far from military activity, mentoring courses on troop training and education. 

Abu Ali Iyad moved to Algeria when it declared its independence in 1962, and contributed to promoting Arabization in that country. 

He participated in Palestinian revolutionary fedayee activity when the Palestinian Revolution was launched on the 1st of January 1965, and in 1966, was tasked with planning military operations to be launched from the West Bank into the occupied Palestinian territory. During this time, Abu Ali Iyad and Yasser Arafat recruited many Palestinians to the Fatah movement. 

On the 25th of April 1966, Abu Ali Iyad led the attack on the Beit Joseph settlement, as well as military operations on the Israeli settlements of Honen, Manara, and Kfar Gileadi. In 1966, he left for Syria to train members of the Fatah Storm Forces, and prepare the Cubs Caravan for the armed Palestinian Revolution. 

Abu Ali Iyad sustained eye and leg injuries when a landmine exploded during a training exercise at Al-Hama military camp in Syria. Though hospitalized, Abu Ali Iyad was elected to the Fatah Central Committee at its 2nd Conference, held in July 1968, in the Al-Zabadani area near Damascus. Along with his military assignments, Abu Ali Iyad was politically active and participated in Palestinian delegations to Arab and Communist states. He made his last visit to China as a member of a Revolution delegation chaired by Yasser Arafat. 

Abu Ali Iyad’s strong relationships with Iraqi commanders facilitated the provision of arms to the Palestinian fedayeen in the battle of Al-Karameh, and with Syrians, who helped to produce the “Fatah Certificate” – a document issued by the Fatah Military Department to expedite access and movement between Arab countries.

In the aftermath of the June 1967 war, Abu Ali Iyad returned to Jordan, where he assigned the command of the Palestinian Revolution Forces in ‘Ajlun and carried out several military operations against Israeli encampments and settlements across the River Jordan. 
In 1970-71, Abu Ali Iyad participated in battles defending the Palestinian Revolution.  He was martyred on the 27th of July 1971, during a battle with Jordanian forces in the Jarash-‘Ajlun forest.