In the years between 2000 and 2010, McLaren was a major force in Formula 1, winning races and championships thanks, in no small amount, to its partnership with Mercedes. A few years later, it was so far off the pace that it had become a backmarker.

The story of McLaren‘s decline is tracked in a video produced by The Race, which argues that troubles can be linked back to the team’s loss of a Mercedes engine, something it has only regained this year, as it finally appears to be edging close to the top of the F1 field.

Ultimately, though, the loss of McLaren’s engine partnership, its controversies, and its fall from grace all come down to bad blood between Ron Dennis and the then head of the FIA, Max Mosley, who died in May.

Read Also: Max Mosley, Former FIA President And Automotive Safety Advocate, Passes Away At 81

The story starts with a look back at the spy scandal that rocked F1 in 2007. The story goes that Nigel Stepney, Ferrari’s disgruntled chief engineer, gave trade secrets to McLaren. When the late Max Mosley discovered this, he stepped in to fine the British team a record $100,000,000 and take away all of its championship points, some say vindictively.

This was galling to Mercedes, which was a part-owner of the team and was therefore on the hook for 40 percent of the fine even though it knew nothing about Stepneygate, as it was then named. The relationship between Mercedes and McLaren was soured, and it was worsened by the impression that McLaren team boss Ron Dennis‘s long-time feud with Mosley was getting in the way of the team’s performance on the track.

In fact, Dennis’ feud with Mosley, who was trying to disempower some of the sport’s biggest teams, led to Mercedes supplying engines to Brawn GP, which would eventually become Mercedes’ works team. In an effort to keep a team on the grid and in the Formula One Team’s Association, Dennis waived McLaren’s veto, allowing Mercedes to supply Brawn GP with an engine.

Following another minor scandal, The Race argues that Mercedes felt it was once again being caught up in a personal battle between Dennis and Mosley, and by 2009 Mercedes bought Brawn GP, relegating McLaren to a simple engine customer. By 2014, Mercedes’ own F1 team was the one winning championships and McLaren had fallen to fifth among the teams with farther left to fall.