The London Marathon is set to make history in 2027, with organisers introducing its biggest change since it first launched. This is expected to be the largest London Marathon ever staged, providing even more opportunities for fundraising as well as larger participation. Marathon detailsThe two-day London Marathon is set to accommodate a staggering 100,000 runners, a significant increase on previous years' single-day events. "London Marathon Events believes the change will raise even more money for charities while allowing tens of thousands more runners to experience the race." A ‘once-in-a-lifetime opportunity'The chief executive of London Marathon Events, Hugh Brasher, hailed the development as a "once-in-a-lifetime opportunity".