Lewis Hamilton will join Mercedes from next season on a three-year contract.
The decision to leave McLaren after a 14-year association with the team has been described by one source close to Hamilton as "the toughest of his career".
In a statement Hamilton said: "It is now time for me to take on a fresh challenge and I am very excited to begin a new chapter racing for the Mercedes Formula One Team. Mercedes-Benz has such an incredible heritage in motorsport, along with a passion for winning, which I share."
He added: "Together, we can grow and rise to this new challenge. I believe that I can help steer the Silver Arrows to the top and achieve our joint ambitions of winning the world championships."
More top news
As a promotion Black Friday is flawed. While it whips up demand and redistributes it the event doesn't obviously generate additional sales.
Jack Garratt follows in the footsteps of Adele, Sam Smith and James Bay as he picks up a Brits Critic's Choice Award.
Rain across much of the remainder of the country