Lewis Hamilton will join Mercedes next season, after McLaren failed to match a lucrative three-year offer, Mercedes confirmed on Friday.
Hamilton will replace seven-time Formula One champion Michael Schumacher, who shifts to McLaren, along with Sergio Perez.
Hamilton, 27, will team with Nico Rosberg next season.
"It is now time for me to take on a fresh challenge and I am very excited to begin a new chapter," Hamilton told reporters. "Mercedes-Benz has such an incredible heritage in motorsport, along with a passion for winning which I share.
"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."
Hamilton won his only Formula One title with McLaren in 2008, but the past two seasons have been controversial. He recently angered management by posting a picture of a telemetry sheet showing data from his and teammate Jenson Button's car on his Twitter page at the Belgian GP. Button publicly criticized Hamilton, leading to rumors that a change was coming.