Sebastian Vettel was part of one of the biggest F1 shocks of the decade when he moved from Red Bull to Ferrari for the 2015 season.

Vettel had won four consecutive championships for Red Bull between 2010 and 2013, before he struggling to fifth in the world championship when F1 cars moved into the hybrid era in 2014.

Nonetheless, few expected the German to then ditch the team he had raced with since 2009 to join Ferrari for 2015, replacing the outgoing Fernando Alonso in the process.

While many believe the opportunity came about after difficult negotiations in 2014 between Alonso and Ferrari over a new deal, Vettel has revealed initial contact started much sooner in a 'secret' meeting.

Ferrari eyed up Vettel move early on

"The first contact came in 2012 after the second title", Vettel said in his new 'Being Sebastian Vettel' documentary.

Vettel claimed he received a congratulatory letter from then Ferrari president Luca di Montezemolo, before further contact was made a year later.

He added: “It was a completely secret meeting. He asked: 'What are the contractual details, would you like to drive for Ferrari?'”

Vettel though declined the approach from Ferrari because he kept winning at Red Bull, despite admitting he was attracted to following in the footsteps of his idol Michael Schumacher who win five straight titles between 2000 and 2004.

He said: "I was very happy at Red Bull and there was no need. Of course, I left the door slightly open.

"It wasn't that I dreamed of being like Michael. But it was a huge magnet that attracted me."

Vettel admits Red Bull situation changed

But after a gruelling 2014 where he was outpaced by new team-mate Daniel Ricciardo, Vettel felt in a position where he could make the move to Ferrari.

He said: "A decisive factor was that I no longer felt secure and therefore couldn't, or wouldn't, perform at my best, so I was ready for a new adventure - to become world champion with Ferrari."

Unfortunately for Vettel, despite helping Ferrari out of their early 2010s doldrums, he was unable to deliver them their first drivers' title since 2007 despite finishing second to Lewis Hamilton's Mercedes in 2017 and 2018.

After being outgunned again by new Ferrari team-mate Charles Leclerc in 2019 and 2020, Vettel moved to Aston Martin for two seasons before ending his F1 career.