PARIS, France - For the first time in the history of Formula 1 six World champions will be on the grid when the season starts on Sunday in Australia. So, here's a snapshot look at each of them (with age, nationality, manufacturer, number of championships, race wins and pole positions).Sebastian VettelAge: 24. Nationality: German. Team: Red Bull. Standing: Double and defending F1 champion. Race wins: 21. Pole starts: 30.Is there anything or anyone to stop Sebastian Vettel joining F1 greats Juan Manuel Fangio and Michael Schumacher as the only drivers to win three consecutive F1 titles? With his Red Bull car already looking like the season's favorite... probably not. Vettel's ability to push his Austrian team's car to its capabilities saw him crush the competition and dominate the championship, winning his second consecutive F1 title with four races to spare.Vettel, nicknamed "Baby Schumacher", has shown an ability to tune out pressure and focus on the track. During 2011 he made fewer mistakes with a more reliable car than during his first championship-winning season. His fun, down-to-earth personality sets him apart from the calculating and businesslike demeanor of fellow German Michael Schumacher.Jenson ButtonAge: 32. Nationality: English. Team: McLaren. Standing: 2009 World champion. Race Wins: 12. Pole starts: 7.Button drove with chilling consistency in the second half of the 2011 season, getting a podium place in eight of the last nine races. He had none in six of the first 10. He won three races and finished second behind overall champion Sebastian Vettel but three places above McLaren's designated No.1 driver, team mate Lewis Hamilton.This will be Button's third season with McLaren. If he continues to blossom, he will be a candidate to win the F1 championship for the second time. While Hamilton may have more speed, the experienced Button, with more than 200 races to his name, is a master at handling changing weather. He proved that by beating Vettel in rain in Canada.Lewis HamiltonAge: 27. Nationality: English. Team: McLaren. Standing: 2008 World champion. Race wins: 17. Pole starts: 19.For Hamilton, the 2011 season was a mixture of off-track distractions, unsavoury clashes with Ferrari's Felipe Massa, and sometimes quite brilliant, if somewhat risky, driving. The Englishman won three races - the most impressive when he tactically outwitted Sebastian Vettel in China - yet he also retired from three races and finished a disappointing fifth overall. He also finished behind his McLaren team mate Jenson Button, the first time he has lost to a team mate in his F1 career.Hamilton's driving ability rivals that of anybody but the 2008 champion needs not only a clearer head for 2012 but also to sort out his contract with McLaren as quickly as possible.Kimi RaikkonenAge: 32. Nationality: Finnish. Team: Lotus. Standing: 2007 World champion. Race wins: 18. Pole starts: 16.Raikkonen expects to pick up where he left off when he returns to F1 despite three years away from the grid. The Finnish driver, who won the 2007 championship title while driving for Ferrari but quit in 2009 and switched to World Rallying and dabbled briefly in Nascar racing, will make a comeback this season with Lotus Renault."Before my two years of rallying I had nine seasons, 157 races and 18 wins in F1," he said. "When I went to rallying and when I tried Nascar, there were many new things to learn, but with F1 I feel like I'm coming home."He geared up for the Australian GP with the best time in the last pre-season test session and seems a certainty to add to his 62 career podiums.Fernando AlonsoAge: 30. Nationality: Spanish. Team: Ferrari. Standing: 2005, 2006 World champion. Race wins: 27. Pole starts: 20.Despite two roller-coaster seasons, Fernando Alonso still believes Ferrari can provide him with a championship-winning car. The double World champion lost the 2010 title to Sebastian Vettel in the last race, three years after losing a chance at the championship because of in-team squabbles with then McLaren team mate Lewis Hamilton.Ferrari, however, is focused on Alonso, who continues to be rated as the best driver on the grid despite his not winning a title since leaving Renault. The team struggled in pre-season testing. Alonso has remained cautious but if Ferrari can find the necessary then you can't rule him out of the title race.Michael SchumacherAge: 43. Nationality: German. Team: Mercedes. Standing: 1994, 9595, 2000, 2001, 2002, 2003, 2004 World champion. Race wins: 91. Pole starts: 68.Schumacher's decision to come out of retirement after three years went flat early in the seven-time World champion's first season two years ago. Mercedes hasn't provided a car to turn that around. The 43-year-old winner of a record 91 races will persevere with a flicker of hope that team principal Ross Brawn can put together a championship winner, although the Silver Arrows seem to have a lot of catching up to do already.Schumacher will probably be pleased with a podium step at this point - an ambition that falls well short of his normal expectations. Schumacher is in the last year of his contract and his future is uncertain.