William and Harry worked from 6am yesterday morning in Datchet, helping with the supply of sandbags. Video footage showed the pair forming part of a human chain with soldiers unloading sandbags from an army vehicle.
Homeowners have been desperate for flood defences as they struggle to protect their properties.
The royal brothers, who were dressed in waterproofs and waders, have served in the military and Harry is still an officer with the Household Cavalry, which has been tasked to help out with flood relief.
A spokesman from Kensington Palace said: “They wanted to show their support for the flood victims and have joined the armed forces relief effort.”
Graham Leaver, the local parish clerk, said: “They were very involved and wanting to know what was going on. They have been in Datchet and the area and I think it’s gone down very well.
“They were very natural. To be honest, they could have walked in among people here and nobody would have recognised them.”