General Lloyd Austin has received US Senate confirmation to become the nation's first black Secretary of Defense.
The retired four-star US Army general has become President Joe Biden's second cabinet member.
But what do we know about him?
Gen Austin is the first black leader Pentagon chief. His appointment came as civil rights leaders pushed Mr Biden to pick more black cabinet members.
The Reverend Al Sharpton said: "It’s a good choice that, I think, many in the civil rights community would support. It’s the first time we have seen a person of colour in that position.
"That means something, in a global view, especially after such an antagonistic relationship we had with the previous administration."
Sources said Mr Biden had picked 67-year-old Gen Austin over long-time front-running candidate Michele Flournoy, a former senior Pentagon official and Biden supporter who would have been the first woman to serve in the role.
Gen Austin retired from the US Army in 2016 and needed a congressional waiver of the legal requirement that a former member of the military be out of uniform at least seven years before serving as Defense Secretary.
That has now been approved. That waiver had been granted only twice previously — most recently in the case of General James Mattis, the retired marines general who served as Donald Trump’s first Pentagon chief.
Until Austin's confirmation, David Norquist was made Acting Secretary of Defense.
Although numerous previous defense secretaries have served briefly in the military, only two — George C Marshall and James Mattis — have been career officers.
Gen Austin was involved in the Iraq War from start to finish. He served as an assistant commander of the 3rd Infantry Division during the invasion of Iraq in March 2003 and oversaw the withdrawal in 2011.
He has had a close working relationship with Biden – especially during the Obama administration when Mr Biden was Vice President.
Gen Austin was commander of the Multinational Corps-Iraq in Baghdad in 2008 when Barack Obama was elected president and returned to lead US troops from 2010 to 2011.
In 2012, he served as the first black Vice Chief of Staff of the US Army – the service’s number two-ranking position.
The following year, he took the reins of US Central Command, where he designed and began implementing a US military strategy for pushing back so-called Islamic State militants in Iraq and Syria.
He earned the admiration of the Obama administration for his work in Iraq and at Central Command, although he disagreed with President Obama’s decision to pull out of Iraq entirely in December 2011.
Upon Gen Austin’s retirement in 2016, Mr Obama praised his "character and competence", as well as his judgment and leadership.
Timing of his appointment
Gen Austin has a reputation for strong leadership, integrity and a sharp intellect.
Mr Biden is reported to have been drawn to Gen Austin because of his oversight of the Iraq pull-out.
His appointment comes at an important time for the US military, which will imminently begin supporting the rollout of the coronavirus vaccine.
Watch: Tobias Ellwood MP, Chair of the Defence Select Committee, said he believes Gen Austin is a "great choice".
What might he mean for the UK Armed Forces?
Colonel (retired) Richard Kemp, former commander of British forces in Afghanistan, said he got to know Gen Austin "very well" whilst in the country.
Col Kemp told Forces News that the new US Defense Secretary’s experience of working with UK troops also includes Iraq and his tenure as Commander of US Central Command.
He said: "I know that from my own dealings with General Austin, in Afghanistan and since then, I know that he has enormous respect and regard for British troops. He’s seen them in action, he’s commanded them in action.
"As our generals, I think pretty much all of them, very much admire American troops, he admires British troops.
"I’ve got one, sort of, slight reservation about his longer relationship with Britain.
"He is a very strong advocate of building and developing alliances, so I think he will see NATO as being the critical alliance of the US and will do all he can, I believe, to strengthen NATO, maybe in the face of opposition from other members of President Biden’s administration."
WATCH: Col Kemp says new US Defense Secretary has "enormous respect" for British troops.
Col Kemp said the reservation he has of Gen Austin’s future relationship with the UK goes back to around 2008, when General Austin was a senior military figure in Iraq.
"I think he was very critical, at the time, of the British performance in Iraq, and I’m not saying he was critical of the British military performance or the way that British troops operated themselves," Col Kemp said.
"He was, I think, more critical of the political will behind the British forces which, essentially, restricted British troops to a relatively low number, probably fewer than they really needed to have and I think the lack of commitment to resolving the situation in Iraq during the time he was there.
"I think he will approach Britain with support for our forces and, no doubt, for the country as well, but will, nevertheless, be looking to see where the land lies now on our political resolve to defend ourselves and also to act, where necessary, as allies with the United States."
Cover image: General Lloyd Austin (Picture: US Department of Defense).