The monarch toured her 20,000-acre Norfolk estate with Edward Parsons as she enjoyed a weekend's rest on doctors' orders. With the help of Mr Parsons, Charles has spent three years transforming Sandringham into an eco concern - planting two million trees, creating 45 new woodlands, planting 25 miles of new hedgerows, and establishing 10 wetlands. Crops include organic wheat, barley, peas and oats and there is a flock of 3,000 sheep and a herd of 500 cattle.

       Mr Parsons told Country Life magazine: "The carbon-cutting toolkit we use suggests, already, the farm's CO2 footprint has reduced by more than 6,000 tons a year."

       The Queen, 95, in her trademark off-duty headscarf and wearing glasses, looked happy and well in spite of concerns after last month's 24-hour hospital visit for "preliminary investigations".

       She had to cancel a two-day visit to Northern Ireland for its centenary and could not attend the COP26 UN climate summit in Glasgow and Saturday's Festival of Remembrance.

       But the Queen insists she will go to the Cenotaph in London on Sunday to pay her respects to the nation's fallen heroes.