Harrovians joined forces on Sunday for the annual Long Ducker fundraising event, raising money for charities supported by the School's Shaftesbury Enterprise.
Boys, some staff, parents and OHs, ran either a sponsored half marathon or 10k starting from Ducker Fields and finishing in Bill Yard.
The event - which also offered an early morning swimming option - is the School's main fundraising event for the local community. Half of funds raised this year will go to Young Harrow Foundation, 25% to The Harrow Club and the final quarter to Cancer Research UK.
Tim Dalton, Director of Shaftesbury Enterprise, said: "We are delighted that our fundraising effort through this year's Long Ducker event will help young people to overcome significant barriers to progress as well as going some way to further medical research."