The Duke of Cambridge and his brother Prince Harry have joined colleagues from the armed forces in helping to defend a town from the floods that have brought misery to much of southern England.
William and Harry worked from 6am in Datchet, Berkshire, helping with the supply of sandbags.
Homeowners have been desperate to get the flood defences as they struggle to protect their properties.
The private visit was unannounced but television camermen and photographers followed the pair once news of their work spread at around 11am.
When Harry was asked by reporters if he was enjoying helping out, he replied: "Not really, with you guys around."
The royal brothers, who were dressed in waterproofs and wellington boots, were seen forming part of a human chain unloading sandbags from an Army vehicle and putting them on to the back of a train wagon.
A spokesman from Kensington Palace said: "They wanted to show their support for the flood victims and have joined the armed forces relief effort."
A Guardian reporter said he was asked by William: "Why don't you put your notebook down and give us a hand with the sandbags?"
But when the journalist agreed to help, aides said he was not wearing the appropriate clothing to carry out the role.
William and Harry have served in the military and Harry is still an officer with the Household Cavalry, who have been tasked to help out with flood relief.
Graham Leaver, clerk at Datchet Parish Council, 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. That is my assessment.
"They were very natural. To be honest, they could have walked in among people here and nobody would have recognised them looking at the way they were dressed.
"They came into our parish office and it took most of us a few minutes to realise they were there. They were particularly interested in talking to the troops. The support we have received from the Army has been absolutely excellent and if they hadn't come into Datchet we as a parish would have been overwhelmed."
He added: "We are all very grateful for the support we have had."
Not only have William and Harry been providing practical help to flood victims but so has the Queen.
A Buckingham Palace spokesman said: "The Queen is supporting Somerset farmers affected by the flooding on the Somerset Levels by contributing feed and bedding from the royal farms at Windsor."