South Staffordshire MP, Gavin Williamson, has been appointed new Defence Secretary, Downing Street has said.
It follows the shock resignation of Sir Michael Fallon on Wednesday in the wake of sexual harassment claims at Westminster.
Sir Michael quit after admitting his behaviour had "fallen below the high standards required" in the role and acknowledging that what might have been acceptable in the past was no longer appropriate.
Mr Williamson, who was the Government's chief whip before this appointment, will replace him in the job, having never held ministerial office.
Mr Williamson left Downing Street with a military officer and got into a waiting car without speaking to reporters.
- Who is Gavin Williamson?
Gavin Williamson got his big break when David Cameron made him his Parliamentary Private Secretary from 2013 to 2016.
When Cameron resigned, Williamson backed Theresa May - who rewarded him by promoting him to her Cabinet as Chief Whip.
His promotion to Defence Secretary is the first time the 41-year-old has held ministerial office.
He is known in Westminster for keeping a pet tarantula named Cronus in a glass box on his desk, which is said to have provided added menace when dealing with errant MPs in his role as Mrs May's 'enforcer'.
Married with two daughters, his background is in manufacturing and design at a pottery in Staffordshire and an architectural design company.
He was awarded a CBE in Mr Cameron's resignation honours for political and public service.