After weeks of speculation, Williams have confirmed that Felipe Massa will join them ahead of the 2014 Formula One season.
In the wake of this year's Italian Grand Prix, Massa announced that he would be leaving Ferrari at the end of the season having spent eight years with the Scuderia.
The 32-year-old was adamant at the time that parting ways with Ferrari would not spell the end of his Formula One career.
Almost immediately rumours surfaced claiming he could be off to Williams although Lotus' name was later added to the list.
However, it is Williams who have secured the 11-time grand prix winner's signature.
"When I was a kid, I always dreamed of racing for Williams, Ferrari or McLaren and I'm glad to be signing with another icon of the sport," said Massa.
The Brazilian is hopeful that new technical director Pat Symonds, who is set to institute a restructure and recruitment programme, will see Williams' fortunes improve next year, as new engine and chassis rules provide what should, at least inititally, be a more level playing field.
"The team wants to grow. It is already a big team but they are really pushing hard to go back to what they were in the past," he said.
"It is a team to fight for the championships and good results and I really want to be a part of it. I understand what they are doing to get stronger. I think we can be very successful and I believe it is the best choice compared to the other choices I had."
Team founder and principal Sir Frank Williams says Massa is "an exceptional talent and a real fighter on the track", while his daughter Claire, the deputy team principal, said: "Felipe has demonstrated his talent and speed over the years, as well as his ability to motivate and drive a team to championship success."
Claire Williams added that acquiring Massa's services was "a key step towards our goal of returning Williams to the front of the grid and part of our ongoing plans to ensure we are stronger in 2014 and beyond".