Tributes have flooded in for German legend Sebastian Vettel, who stunned the motor racing world on Thursday by announcing that he would be calling time on his distinguished Formula 1 career at the end of this season. 

Arguably one of the best racing drivers the sport has ever seen, Vettel won four consecutive F1 world titles with Red Bull between 2010 and 2013. Only Michael Schumacher, Lewis Hamilton and Juan Manuel Fangio have clinched more.  

The 35-year-old made his F1 debut in 2007 and bagged 53 Grand Prix victories, which put him third on the all-time list. He became the sport's youngest world champion after beating Fernando Alonso to win the title at 23 years and 134 days old in 2010.

A legend and role model 

Seven-time champion Hamilton, who made his debut the same year as Vettel, described him as "one of the most impactful F1 drivers who has ever lived." 

"Sebastian, it's been an honor to call you a competitor and an even greater honor to call you my friend," he said on Twitter. "Leaving this sport better than you found it is always the goal. I have no doubt that whatever comes next for you will be exciting, meaningful, and rewarding. Love you, man." 

Double world champion Alonso said, "Four titles and not only a legend as a driver, as a human being. He has very strong values and a very correct way of thinking. We will miss him. I will miss the battles on track. 

"Our careers were very close together always, together with Lewis. We miss one of the three. But family and other things are probably in this decision so I wish him the best and a lot of happiness."

Alonso's sentiment was echoed by last season's world champion Max Verstappen, who said, "He is a great ambassador for the sport and has achieved so much. He worked hard for that." 

Ferrari's Carlos Sainz said, "He's a great role model, and an ambassador for the sport, but also the younger generation coming through... We will miss him but I hope we will see him again in the paddock helping in some of the areas he has been very vocal about recently." 

Schumacher's son Mick also paid his tribute, adding, "I'm so sad that you're leaving, but at the same time excited for you and this new chapter of your life. You've been and still are such an important person to me and I'm thankful for our friendship.  

"Thank you for everything you've contributed to the sport we both love, I can't wait for our last races together. Thank you, Seb – you're an inspiration."

End of an era 

Last season, Vettel moved to Aston Martin and finished 12th. His two-year deal expires this year, and multiple media outlets have confirmed that Aston Martin wanted him to stay on for a third year, but he decided he wanted to step away from the sport.  

"The decision to retire has been a difficult one for me to take, and I have spent a lot of time thinking about it," said Vettel in a video posted on his Instagram.  

"I love this sport. It has been central to my life since I can remember. But as much as there is life on track, there is my life off track too. Being a racing driver has never been my sole identity. I very much believe in identity by who we are and how we treat others rather than what we do.

"I believe in change and progress and that every little bit makes a difference. I am an optimist and I believe people are good. Next to racing, I have grown a family and I love being around them. I have grown other interests outside Formula 1. My passion for racing and Formula 1 comes with lots of time spent away from them and takes a lot of energy. 

"Committing to my passion the way I did and the way I think it is right, does no longer go side by side with my wish to be a great father and husband. The energy it takes to become one with the car and the team, to chase perfection takes focus and commitment." 

Vettel said he had not decided what to do next, adding, "Today is not about saying goodbye. Rather, it is about saying thank you, to everyone, not least to the fans, without whose passionate support F1 could not exist."