Ron Dennis has staged an internal coup and wrestled back control of the McLaren Formula 1 team.
Dennis, who stood down as team principal in 2009 and had been at loggerheads with the board, has been appointed chief executive officer.
He replaces Martin Whitmarsh, whose role as team principal is under threat.
No-one at McLaren has been sacked or made redundant. The identity of their team principal from 2014 will be announced next month.
McLaren have not said whether Whitmarsh will lose his position as team principal, but it must be considered highly likely.
Dennis - who has been made chief executive officer of the McLaren Group - has been in dispute with Whitmarsh over the last two years.
On several occasions, Dennis has tried to remove his former protégé from his position.
He had failed because of his fractured relationship with the other board members. It is not immediately clear how that has been repaired.
Dennis told the McLaren staff on Thursday that "there will be change" and "we will win again".
In December, Dennis said that he had spoken about the future with former Mercedes team boss Ross Brawn, who will be considered a front-runner to be McLaren's new team principal once he has finished a planned six-month sabbatical.
A senior McLaren insider told BBC Sport that Dennis did not want to return to a role on the pit wall at races.
Dennis, who is also the non-executive chairman of the McLaren Group, has been dissatisfied with the performance of the F1 team for some time.
They had their worst season for three decades in 2013, failing to score a podium finish for the first time since 1980, before Dennis took full control of McLaren.
The team have not won a drivers' world championship since Lewis Hamilton in 2008, and have failed to win the constructors' title since 1998.
Dennis said in a McLaren statement that the company's shareholders had "mandated me to write an exciting new chapter in the story of McLaren, beginning by improving our on-track and off-track performance".
He added: "Over the coming weeks I intend to undertake a thorough and objective review of each of our businesses with the intention of optimising every aspect of our existing operations, while identifying new areas of growth that capitalise on our technologies, and where appropriate further investing in them.
"During February, I will articulate a new Group strategy and implement the organisational structure best suited to achieving it."
There has been no change in the company's shareholding. The Bahrain royal family's Mumtalakat investment fund still owns 50%, with Dennis owning 25% and his long-time partner Mansour Ojjeh the remaining 25%.
Ojjeh is recovering from a double lung transplant and has temporarily relinquished his role as a director to his bother Aziz.
Dennis remains in his role as chairman of McLaren Automotive.
Whitmarsh had been trying to persuade Ferrari driver Fernando Alonso to join the team in 2015.
Dennis's new role must now make that highly unlikely as the two fell out in dramatic style when the Spaniard drove for McLaren in 2007.
Last month, Dennis told BBC Sport that he would not have a problem with the two-time champion returning to the team but Alonso himself has made it clear he still blames Dennis for their past problems.
Alonso is anyway under contract to Ferrari until the end of 2016, although his relationship with the Italian team cooled during a troubled 2013 season.