Lewis Hamilton's relationship with Nico Rosberg hit a new low on Sunday following their dramatic crash in the Spanish Grand Prix.
Here, Press Association Sport takes a closer look at the Mercedes team-mates and Formula One's other famous rivalries.
James Hunt and Niki Lauda - 1976
Hunt, the English playboy versus Lauda, the dedicated Austrian. Lauda disliked Hunt's so-called lack of professionalism - the Englishman was a heavy drinker and smoker - while McLaren's Hunt diminished his rival's appearance by labelling him a rat. Lauda, racing for Ferrari, took the early lead in the championship before his near-fatal crash at the Nurburgring. Incredibly he returned to the cockpit just six weeks later, missing three races, but lost the championship to Hunt by a single point after he chose to withdraw from the rain-soaked decider in Japan on safety grounds.
Nigel Mansell and Nelson Piquet - 1986, 1987
Piquet signed for Williams as the team's new number one driver, but nobody informed Mansell. An incredibly tense relationship thus ensued with Mansell refusing to roll over. They took points off each other throughout the 1986 campaign before Mansell's tyre blow-out at the final race in Adelaide afforded Alain Prost the title. Piquet won the championship the following season, but largely by default, after Mansell missed the final two races.
Ayrton Senna and Alain Prost, 1988-1990
Probably the greatest rivalry in Formula One. Senna, the naturally-gifted Brazilian, went toe-to-toe with Prost, the so-called professor, in three fascinating seasons. Senna won the championship in the first year, but their time together at McLaren soon descended into chaos. They collided in the decisive race of the 1989 campaign in Japan. Senna recovered to win after Prost retired, but the Brazilian was subsequently disqualified with Prost claiming the title. Prost joined Ferrari but another crash, again in Japan, enabled Senna to win the title.
Sebastian Vettel and Mark Webber - 2010-2013
Team-mates Webber and Vettel collided at the 2010 Turkish Grand Prix and from there, the relationship was beyond repair. Webber subsequently accused Red Bull of favouritism towards Vettel - "not bad for a number two driver", he said after winning the British Grand Prix in 2010. Vettel then passed Webber to win in Malaysia in 2013, despite being instructed not to do so by his team. Vettel, however, won four championships and Webber won none.
Lewis Hamilton and Nico Rosberg 2013-
While the childhood friends enjoyed an amicable relationship in their first season at Mercedes, the intensity was ramped up when their team became the force of the field in 2014. They fell out in the Monaco race of that season after Hamilton accused Rosberg of deliberately botching his qualifying lap - with the latter securing pole - before they collided in Belgium. Hamilton was forced to retire and Rosberg was blamed. Their frosty relationship then came to ahead again in Barcelona following their opening-lap crash. Hamilton has won two championships at Mercedes, while Rosberg, 43 points ahead of his team-mate this season, is yet to open his account.
Source: PA
