Patrick Head will tonight walk away from direct involvement in Formula 1 after 34 years active service with the Williams team, having stepped down from the outfit's board of directors with immediate effect.
Head, whose role with Williams was director of engineering, revealed his intention to back away from the sport at the Brazilian Grand Prix, following on from a technical and management restructure prompted by the teams' worst campaign in its history during 2012.
Head has chosen to focus on the company's thriving hybrid business and will remain a board director of Williams Hybrid Power Limited, but will not have any operational duties within the F1 set-up.
"I certainly did not have an ambition to end my involvement in F1 with the season I have just had behind us," he told AUTOSPORT at the end of November. "But when I have a look at what specifically I can do to assist Mike Coughlan, and Mark Gillan and Jason Somerville, I came to the conclusion that it isn't enough for me to carry on justifying doing the same thing.
"It is not interesting for me; it is not good for the company. I decided to have a change of focus now."
The 65-year-old added at the time that he had no intention to retire from work just yet.
"Certainly it is not the word retirement but I am not going to be directly part of the Williams F1 programme next year," he said.
"I am going to be doing some work for Williams Hybrid Power, which may sound a bit dry and dull but it is actually quite high tech and quite interesting."
In a statement released by the team, Frank Williams paid tribute to his long-time partner and friend: "Patrick and I have been in partnership for 34 years. During that time, he has been the leader of the technical team that has won the majority of our race wins and championships.
"This is a remarkable legacy and one which will be treasured and definitely not forgotten.
"Patrick is a very straightforward, hard working and truly gifted engineer who comfortably operates at a world class level. I will miss him very much, as I am sure his colleagues will, and he will always be welcome at Grove. Indeed, Patrick will still be seen around the factory as he continues to be involved in the development of our hybrid power activities."
Head began his motorsport career with Lola after graduating from London University in 1970. He formed Williams Grand Prix Engineering with Frank Williams at the end of 1977, having previously joined Williams' former team before he had sold to Walter Wolf a year earlier.
Head took a 30% stake in the new Williams team and together with Frank they went on to conquer the sport through the 1980s and '90s. During the period in which Head was actively a force in the team's engineering department it won 113 grands prix, secured seven drivers world championships and nine constructors' titles.
Williams remains Formula 1's third most successful team behind Ferrari and McLaren.