Josh Kerr broke one of track and field’s longest-standing world records Saturday, running a mile in 3 minutes, 42.66 seconds at the London Diamond League meeting to shatter Hicham El Guerrouj’s 27-year-old mark, completing an eight-month training project the British runner had publicly dubbed “Project 222.”

The record, previously set at 3:43.13 by Morocco’s El Guerrouj in Rome in July 1999, had stood as one of the oldest and most revered marks in outdoor track and field. Kerr’s winning time shaved 0.47 seconds off that record, finishing well clear of the field at London Stadium in a performance that fulfilled a goal he had announced publicly months in advance, naming the effort “Project 222” after his target time of 222 seconds, or 3 minutes 42 seconds.

Kerr, 28, executed the race with the help of pacemakers who guided him through the early stages at a precise, metronomic pace. His Brooks Beasts teammate Brandon Kidder led him through the first 800 meters, before Zan Rudolf took over pacing duties through the 1,000-meter mark. Kerr then closed out the race on his own, splitting laps of 54.75, 55.88 and 55.76 seconds to reach the bell before pulling away decisively over the final lap. American record-holder Yared Nuguse chased Kerr over the closing stretch but ultimately finished more than three seconds behind in a season-best time of 3:45.69, with Jake Heyward also unable to keep pace with the Scottish runner down the home straight.

Speaking to reporters on the track immediately after the race, Kerr was quick to credit the team around him rather than take individual ownership of the achievement. “That was not me, that was my team every single step,” Kerr said, referencing the extensive support Brooks, his longtime sponsor, had provided in developing a bespoke racing spike and speed suit specifically engineered for the record attempt.

Kerr’s build-up to the record attempt had been unusually public for an athlete targeting a world record of this magnitude. Speaking to the BBC ahead of the race, Kerr described the mile world record as one of the sport’s most significant benchmarks. “It’s been a huge goal of my career. It’s one of the oldest world records on the track and I think it’s one of the most important ones,” Kerr told BBC Sport. “It has stood the test of time and needs a huge amount of respect. With the training numbers that we’re putting up, I think this year is such a great opportunity to have a real crack at it while not giving up other opportunities.”

Kerr entered the 2026 outdoor season on the back of a successful indoor campaign, having won his third career world title by claiming gold in the indoor 3,000 meters in Toruń, Poland, holding off a late charge from Olympic 1,500-meter champion and 5,000-meter world champion Cole Hocker. That performance capped Kerr’s return from a torn calf muscle suffered during his failed defense of the outdoor 1,500-meter world title in Tokyo roughly six months earlier. With no outdoor world championship scheduled for 2026, Kerr and his team made the decision to redirect his focus toward El Guerrouj’s mile mark, a target Kerr said carried special significance given the record’s age and stature within the sport.

In an interview with Olympics.com ahead of the attempt, Kerr framed the pursuit as part of a broader mission to elevate the profile of middle-distance running. “This is the legacy I’m going to leave for the sport. Showing the next generation what it takes to go after big records like this and to dominate a distance where it’s hard to find the guy who will do that consistently,” Kerr said. “I’m here to do the big things and hopefully continue to elevate the sport as much as I can. Not announcing that is not in my character.”

Ahead of the record attempt, Kerr used a tune-up race at the LA Track Fest to sharpen his speed over shorter distances, clocking a personal best of 1 minute, 44.60 seconds in the 800 meters as part of his preparation. Kerr’s previous personal best in the mile stood at 3:45.34, a mark he set in 2024 when he broke Steve Cram’s 39-year-old British mile record at a Diamond League meeting in Eugene, Oregon, defeating Norwegian rival Jakob Ingebrigtsen in that race. Saturday’s world-record performance improved on that previous personal best by nearly three seconds, a substantial jump for an athlete already ranked among the world’s fastest milers.

Kerr’s rivalry with Ingebrigtsen has been a defining storyline of his career in recent years, dating back to his upset victory over the Norwegian in the 1,500 meters at the 2023 World Athletics Championships and continuing through their close battle at the Paris 2024 Olympics, where Kerr took silver behind Hocker. Cram, who set his own British mile record in 1985 and later became a BBC commentator, praised Kerr’s development following his 2024 Eugene performance, saying at the time that Kerr was “getting better and better and better.”

Saturday’s race also carried added weight given the venue. Kerr competed in front of a home crowd at London Stadium, a factor he had specifically cited as adding significance to the attempt. He is also set to compete for Commonwealth gold in the mile on home soil in the weeks following Saturday’s Diamond League meeting, giving the London record attempt additional context within his broader 2026 season plans.

With El Guerrouj’s mark now broken, Kerr’s 3:42.66 becomes the new benchmark for the men’s mile world record, a distance and event long considered one of track and field’s most storied and closely watched, dating back generations of milers who have chased sub-four-minute and record-setting performances on the world’s biggest stages.