Daniel Ricciardo has brought the world of Formula 1 to a stand-still after agreeing to leave Red Bull for Renault at the end of this season.Renault confirmed the news, that will see the Aussie join current driver Nico Hulkenberg. This means that Carlos Sainz will look for a new team to race for, with McLaren or Red Bull looking to be his likely destinations.Ricciardo finalised negotiations with the French works team and has committed his future to them from 2019, dealing a massive blow to Red Bull.He said: "It was probably one of the most difficult decisions to take in my career so far."I realise there is a lot ahead for Renault to reach their target of competing at the highest level, but I have been impressed by their progression in only two years."The 29-year-old is believed to have also been in contact with McLaren over a potential deal, but those talks amounted to nothing.Well, he has already received a warm welcome from his future teammate Hulkenberg in the form of a nice tweet.Shortly after the news broke, Hulkenberg tweeted Ricciardo: "Welcome to the family bro, looking forward to going hunting together next year!"

Ricciardo was supposedly tired of being in team-mate Max Verstappen's shadow after Red Bull appeared to make the Dutchman their number one last year - despite Ricciardo remaining loyal to the team for five years.

Interestingly, the Australian sits 13 points ahead of Verstappen in fifth in the 2018 overall standings. 

Red Bull's team principal Christian Horner hammered the final nail into the coffin last season when he offered Verstappen an improved deal, declaring him as number one and saying the team would now be built around the Dutchman.

In a recent statement, Horner thanked Ricciardo's contributions to the team over the years.

He said: "We fully respect Daniel's decision to leave Aston Martin Red Bull Racing and we wish him all the best in his future.

"We would like to thank him for his dedication and the role he has played since joining the team in 2014. 

"We will now continue to evaluate the numerous options available to us before deciding on which driver partners Max Verstappen for the 2019 season."

Given Ricciardo's comments earlier this week insisting he'll focus on penning a new deal with Red Bull during the summer break, the news comes as a surprise to many and will likely prompt a number of other driver changes throughout the paddock.