Hezbollah has confirmed the martyrdom of its leader, Sheikh Hassan Nasrallah after Israel claimed that it had killed him in an airstrike on Beirut.

Born in 1960, Nasrallah grew up in the neighbourhood of Bourj Hammoud in Beirut. He was the key force in turning Hezbollah into the political and armed force it is today.

He became secretary general of Hezbollah in 1992 aged just 35, the public face of a once shadowy group founded by Iran's Revolutionary Guards in 1982 to fight Israeli occupation forces.

Israel killed his predecessor, Sayyed Abbas al-Musawi, in a helicopter attack. Nasrallah led Hezbollah when its guerrillas finally drove Israeli forces from southern Lebanon in 2000, ending an 18-year occupation.

Since his acceptance of the role, Hezbollah helped train fighters from the Palestinian resistance group, Hamas as well as fighters in Iraq and Yemen. The group obtained missiles and rockets from Iran to use against Israel, as per BBC. 

Nasrallah will be remembered among his supporters for standing up to Israel and defying the United States. He was a revered leader as well as a freedom and occupation fighter.

His regional influence has been on display over nearly a year of conflict ignited by Israel’s offense on Gaza, as Hezbollah entered the fray by firing on Israel from southern Lebanon in support of its Palestinian ally Hamas, and Yemeni and Iraqi groups followed suit, operating under the umbrella of "The Axis of Resistance".

"We are facing a great battle," Nasrallah said in an August 1 speech at the funeral of Hezbollah's top military commander, Fuad Shukr, who was killed in an Israeli strike on the Hezbollah-controlled southern suburbs of Beirut.

Yet when thousands of Hezbollah members were injured and dozens killed, when their communications devices exploded in an apparent Israeli attack last week, that battle began to turn against his group.

Responding to the attacks on Hezbollah's communications network in a September 19 speech, Nasrallah vowed to punish Israel.

"This is a reckoning that will come, its nature, its size, how and where? This is certainly what we will keep to ourselves and in the narrowest circle even within ourselves," he said.

He had not given a broadcast address since then.

Israel has meanwhile dramatically escalated its attacks, killing several senior Hezbollah commanders in targeted strikes and unleashing a massive bombardment in Hezbollah-controlled areas of Lebanon, which has killed hundreds of people.

Recognised even by his enemies as a skilled orator, Nasrallah's speeches are followed by friend and foe alike.

Nasrallah used his addresses to rally Hezbollah's base but also to deliver carefully calibrated threats, often wagging his finger as he did so.