The 86-year-old, a keen hunter, was captivated by a new spy plane designed to help farmers manage their land that he saw during a visit to Aberystwyth University in Wales.

But it transpired that it was not the inventive use of technology to help farmers decide how much fertiliser to use, which crops to harvest and where best to graze livestock that had interested Prince Philip.

“He even asked whether the technology could be used to spot deer,” says project manager Alan Gay.

Oh dear, indeed.