Britain's triple world champion Lewis Hamilton will be partnered by Valtteri Bottas at Mercedes for the new Formula One season.
Bottas, the 27-year-old Finn who joins from Williams, becomes Hamilton's fifth team-mate in the sport.
Here, Press Association Sport looks at how Hamilton has stacked up against his previous team-mates, and how Bottas may fare against the Brit.
FERNANDO ALONSO (2007)
Rookie Hamilton was expected to have his work cut out to match Alonso after he was handed his grand prix debut with McLaren back in 2007. Alonso arrived at the British team as the reigning champion following back-to-back triumphs with Renault. However, Hamilton did not only match Alonso, but beat his team-mate on a number of occasions, too. Alonso, given his status as world champion, felt he warranted clear number one status at the team. But this was never forthcoming and his rivalry with Hamilton spilled over in Hungary after Alonso deliberately blocked his team-mate from challenging for pole. A mass fall-out ensued and Alonso quit the team after just one season. They both won the same number of races and finished level in the championship, one point behind eventual winner Kimi Raikkonen.
HEIKKI KOVALAINEN (2008-2009)
Following Alonso's departure, McLaren moved to sign Kovalainen from Renault. Hamilton wiped the floor with the Finn in their opening year, while fending off Ferrari's Felipe Massa to win the his maiden title by one point (Kovalainen finished a distant seventh). Hamilton was unable to defend his championship in a below-par McLaren, but still finished the season with more than double the points of his team-mate.
JENSON BUTTON (2010-2012)
After his shock championship win at Brawn GP, McLaren moved to sign Button. He formed a fascinating all-British line-up with Hamilton, but some questioned the wisdom of Button's move given Hamilton's reputation as the quicker of the pair. Button however, proved to be a much sterner challenge for Hamilton than most had predicted. While Hamilton beat Button on points in their opening campaign, the roles were reversed in 2011. Indeed Button became the first team-mate to beat Hamilton over the course of a season, and while Hamilton finished ahead of Button the following term, Button ended their three-season stint with more points than his team-mate.
NICO ROSBERG (2013-2016)
Hamilton joined Mercedes to partner Rosberg at Mercedes after ending his six-year tenure with McLaren. Mercedes gave the former karting team-mates a romantic billing, but their relationship soon turned sour as the intensity of going head-to-head for the title took its toll. Hamilton finished ahead of Rosberg in their opening year, and then beat him to the title in 2014 (at the final race) and 2015 (with three grands prix to spare), but Rosberg finally got the better of Hamilton last season by clinching the title at the season-ending race. Five days later the German retired.
VALTTERI BOTTAS (2017-)
Rosberg's shock decision to retire paved the way for Bottas to join from Williams. The Finn is seen as a steady, easy-going driver, and one who is unlikely to cause friction within the team - something Mercedes may welcome following Hamilton and Rosberg's intense relationship. While Bottas impressed on occasions at Williams, how he will fare in a world championship-winning car, alongside arguably the finest driver of his generation in Hamilton, is somewhat of a mystery. But what is certain is that nobody expects Hamilton to be beaten, and that the British driver will be desperate to make up for his title defeat last year.
Source: PA
