Saad Hariri's journey to becoming Lebanon's prime minister began after the 2005 assassination that killed his father Rafik, and ended with a televised address in which he voiced concern that he may meet a similar fate.

The younger Hariri's November 2017 resignation, which came after just 11 months in power, ended his second stint as prime minister, a role set aside exclusively for members of Lebanon's Sunni community.

He assumed office in December 2016 as prime minister in a power-sharing government headed by President Michel Aoun, a supporter of Hezbollah, whose members have been charged by the International Court of Justice with assassinating Rafik Hariri.

After his father's death, Hariri went on to the Future bloc (al-Mustaqbal), which draws its support mainly from the country's Sunni population, and which later formed alliances with other parties from across Lebanon's communal divide.

His first stint as prime minister came in 2009 but was only slightly longer than his most recent, lasting just 19 months, and failing in 2011 after ministers aligned with Hezbollah resigned while Hariri was in Washington, DC, meeting the then-US President Barack Obama.

The Shia group and its patron Iran were the focus of Hariri's resignation speech on Saturday, which was made in Saudi Arabia, where he holds citizenship.

He blamed Iran for "disorder and destruction" in Lebanon and called Hezbollah "Iran's arm", which had imposed a "fait accompli on Lebanon through the power of its weapons".

Kamel Wazne, a Lebanese political analyst, described the resignation as "a surprise coup by all measures".

He told Al Jazeera Hariri "probably caved in to the demands of the Saudis ... [which] does not bode very well for the stability of Lebanon".

Important figure

Born in Saudi Arabia on April 18, 1970, Saad Hariri went on to head his father's Saudi-based construction company, Saudi Oger, one of the largest companies in the Middle East.

When Saad Hariri entered Lebanese politics following his father's death four years ago, critics chided him for his lack of political experience.

However, a decade after the assassination, the younger Hariri remains one of the most important figures in Lebanese politics and is very likely to continue playing a role after his resignation.

Imad Harb, a political analyst at the Arab Center in Washington, DC, told Al Jazeera that for Hariri to make the announcement in Riyadh "basically means he can't have control over his government or his country.

"Hezbollah has been in control of the Lebanese state for quite a while and now it's a supposed victory in Syria on the side of the Syrian regime."

Harb was referring to Hezbollah's role in fighting alongside forces of Syrian President Bashar al-Assad, who has slowly taken back control over his country following a six-year civil war.

"This has definitely affected Hariri's decision to resign, I have no doubt that maybe he is afraid for his life."