Captain Tom Moore, who fought in Burma and India, has walked the marathon in his back garden using a walker to complete the 100 laps around his yard.
Moore originally set out to raise £1,000 for the National Health Service, as his contribution to fighting the global coronavirus epidemic. But after media drew attention to his project, donations soared and he ended up raising a staggering $17.5 million.
When he completed the marathon, he was saluted by a special guard of honor and told the BBC's reporter that he was feeling "fine" and that health workers were the new heroes who "deserve everything we can give them."