It’s the move that the Formula 1 world has been expecting for months, but as James Allen explains, the Alonso to Ferrari deal for 2010 has only been definitively concluded in recent weeks.
The itv.com/f1 columnist also looks at why it has been Raikkonen, and not Massa, who has been forced to make way for his generational rival, while also explaining why F1 is set to be the real winner from this particular driver merry-go-round.
Fernando Alonso joining Ferrari was the worst kept secret in recent F1 memory.
The Spaniard was first mooted as a Ferrari driver in December last year and the rumours have swirled around ever since.
But it was really only in the last few weeks that the deal has come together.
There was an understanding between them that had either 2011 or 2010 as the start point depending on how the season panned out.
Ferrari took their time over deciding what to do.
As of Spa it was still not clear exactly which way they were heading.
At Monza came the scheduled announcement that Santander would be joining the Ferrari team.
The deal is a big one, in the region of €45 million a season.
When you consider that they still have Philip Morris and other sponsors, that their share of the TV and prize money is $50 million and they get an extra payment for their historic status in F1, they are very well funded for the new-look F1 where budgets are supposed to come down to below €100m in 2010 and then down to around €60 million in 2011.
Alonso will drive alongside Felipe Massa.
Many people are surprised that it is Raikkonen who is making way when Massa is the cheaper driver to pay off and it is not clear yet that he will be his old self when he gets behind the wheel.
However Ferrari clearly feels that the brave little Brazilian is part of the family and they would not dump him when he is at his most vulnerable.
This would play badly in Italy and around the world.
Also the reasons for dropping Raikkonen stretch back through his time with the team. He has a very different way of working from Michael Schumacher, he has a social life which is oriented very differently from the Italian way and it wasn't such a great fit.
You have to admire Kimi for being his own man, but I think he will regret not trying to fit in to what they expected of him.
He achieved his dream, to win the world championship and you can bet that he will be massively motivated to do it again in a McLaren to show Ferrari and everyone else how good he is.
Lewis Hamilton will have a tiger by the tail next season, if they end up as a pairing.
As for Alonso, he will go well at Ferrari. He's intelligent, fast, organised and ruthless. He is the leader they have been lacking.
And the rivalry between Alonso, Hamilton and Raikkonen is going to make F1 one of the most compelling spectacles in sport in the coming years.