Jared Kushner arrived at the White House with the broadest of briefs and has come out on top of several rounds of infighting in the West Wing.
But he has faced several power struggles and has at times fought to remain relevant in Trump's revolving door administration.
Mr Kushner, who had no prior government experience, became a senior adviser to his father-in-law President Donald Trump.
The 37-year-old's previous main work experience was running his father's real-estate firm.
Despite having no diplomatic credentials, he was tasked with no less a challenge than resolving the Israeli-Palestinian conflict and also became the president's lead adviser on relations with China, Mexico and Canada.
Mr Kushner, who is married to Mr Trump's daughter Ivanka, was also tasked with leading a bureaucracy-busting White House office whose ambitious remit ranged from reforming veterans' care to liaising with Mexico.
But the man dubbed the Secretary for Everything by US media suffered a stunning reverse a year into his father-in-law's presidency.
Mr Kushner was stripped of his interim security clearance in February, which barred him from viewing documents the US classifies as top secret. He was also excluded from key Oval Office meetings, before he eventually received a permanent clearance months later.
The downgrade came as the Washington Post reported officials in China, Israel, the United Arab Emirates and Mexico had privately discussed how to use Mr Kushner's business interests as leverage over him.
Mr Kushner's marginalisation in the West Wing came amid reports of a power struggle with White House chief of staff John Kelly, who made the decision on downgrading his clearance.
Mr Kelly has stared down many enemies in his career as a former US Marine Corps general, but he may have met his match in Mr Kushner, a man who has seen off other White House officials in Steve Bannon and Reince Priebus.
Mr Trump once described his son-in-law as "very good at politics".
US Ambassador to the UN Nikki Haley told the president his son-in-law is a "such a hidden genius that no one understands".
And Mr Kushner seemed to justify those assessments during the 2016 White House campaign, proving himself adept at outmanoeuvring rivals.
When combative campaign manager Corey Lewandowski was fired before the election, it was reportedly Mr Kushner who pushed for him to get the chop.
Jared Kushner was born and raised in Livingston, New Jersey, alongside two sisters and a brother.
An Orthodox Jew, his grandparents were Holocaust survivors who arrived in the US in 1949. His father Charles made his fortune as a New Jersey property mogul.
The young Jared won a place at Harvard despite poor grades, according to Daniel Golden, author of The Price of Admissions: How America's Ruling Class Buys Its Way into Elite Colleges.
The year of his admission, according to Mr Golden's book, Charles Kushner donated $2.5m to the university, along with similar one-off donations to Cornell and Princeton.
In 2006, at just 25, Mr Kushner bought the New York Observer, but his tenure was not plain sailing.
The newspaper's respected editor of 15 years, Peter Kaplan, resigned three years after Mr Kushner took over following clashes between the two.
Six other editors were recycled in quick succession over the next seven years, before Mr Kushner severed ties to the Observer as he joined the White House.
In 2008, he took over his family's company after his father was jailed for tax evasion, illegal campaign contributions and witness tampering.
Mr Kushner Snr had admitted setting up his own brother-in-law with a prostitute, secretly filming the liaison, and sending the tape to his sister in an effort to prevent them testifying against him.
He was pardoned by Mr Trump in the last weeks of his presidency.
In 2009, Jared wed Ivanka Trump at a Trump golf club in New Jersey. They have three children.
Mr Kushner and Mr Trump's apparent bond may be based in part at least on similar experiences.
Both are political outsiders who inherited property empires from their fathers at a relatively young age. The Kushners own 666 Fifth Avenue, a Manhattan skyscraper just a few blocks from Trump Tower.
Mr Trump's father, Frederick Christ Trump, was also a controversial figure who was taken to court on claims of racial discrimination in housing allocation.
But in contrast to his father-in-law, Mr Kushner is a camera-shy personality.
This fresh-faced, behind-the-scenes operator has also been questioned as part of a Senate investigation into alleged links between the Trump campaign and the Kremlin.
Mr Kushner not only spoke to Moscow's ambassador in December 2016, but met the head of a US-sanctioned, Russian state-owned bank.