London Marathon has never done anything quite like this.

On 24-25 April 2027, the TCS London Marathon will become a two-day event for the first and only time, with 100,000 runners taking on the traditional 26.2 miles from Greenwich to Westminster.

And while the streets belong to London, the story belongs to runners across Britain. A world record 1,338,544 people applied through the ballot, including 1,008,091 from the UK. Saturday will accommodate 45,000 runners and Sunday another 55,000, with mixed mass participation fields on both days.

The elite races will be split too. The men and men's wheelchair races go on Saturday, with the women and women's wheelchair races opening Sunday. Amusingly, that order was decided by a Guinness World Record setting game of Rock, Paper, Scissors between reigning champions Sabastian Sawe and Catherine Debrunner. Debrunner won.

There is considerably more at stake when the racing begins. London will host the UK Athletics Marathon Championships and act as the official trial for the 2027 World Athletics Championships in Beijing. Performances will also form part of the selection process for the LA 2028 Olympic Games.

Beyond racing, organisers believe the Double can raise more than £150 million for charity, creating the largest fundraising moment in UK sporting history.

Even the Friday will be huge, with more than 20,000 youngsters expected for the Mini London Marathon.

From Britain's best marathon runners chasing global championships to tens of thousands pursuing very personal finish lines, London 2027 will be something entirely new.

Two days. One course. 100,000 runners. The biggest London yet.

You can still secure a charity place via the runABC race hub.

Image courtesy London Marathon Media.