Mustapha Adib, a little-known diplomat tasked with forming a new crisis government to save Lebanon from the brink, resigned Saturday after less than a month as premier designate.
Adib was named on August 31 to replace Hassan Diab, whose government resigned in the aftermath of the deadly August 4 blast at Beirut's port.
Until then, he had been Lebanon's ambassador to Germany since 2013.
The 48-year-old was born in the northern city of Tripoli. His biography on the Berlin embassy website presents him as an academic who holds a PhD in law and political science.
It says he has conducted "research and expert work in the areas of both human and state security, parliamentary oversight of the security sector, decentralization and local democracy, and electoral laws".
From 2000 to 2004, he served as an adviser to Najib Mikati, a billionaire former prime minister who backed his nomination.
In 2011, then-premier Mikati appointed Adib as his chief of cabinet.
Former premiers Saad Hariri and Fouad Siniora also threw their weight behind Adib, after two other candidates were reportedly rejected by the Iran-backed Hezbollah party and its political allies.
An acquaintance from Tripoli, who asked not to be named, described Adib as "calm, courteous and diplomatic".
"He is not a man of confrontation," the acquaintance told AFP.
Mohammed Dhayby, 40, one of his former students, said that when Adib taught at the Lebanese University's law faculty in Tripoli in 2000-2001, he was just 28.
"He was a timid professor at the time, and if he hadn't been wearing a suit, we wouldn't have believed he was a university professor at all."
Opposition groups representing the protest movement that erupted last year to demand the wholesale removal of a political class seen as corrupt and incompetent had rejected Adib's nomination before it was even confirmed.
Activists on social media were quick to compare Adib to Diab, who had promised to lead Lebanon's first government of technocrats when he took office in January but showed no ability to break from his political sponsors.
Lebanon Rises Up -- Germany, a Facebook page representing Lebanese activists in Germany, told AFP that Adib was a product of the past and could not embody change.
It claimed that Adib himself, who was not a career diplomat when he was appointed to Berlin by a Mikati government, owed his job to the former prime minister and to Lebanon's sectarian quotas.