A pair of white storks are set to become the first to breed in the wild in Britain since the 15th century.

Nesting on an ancient oak tree on the 1,400-hectare rewilded Knepp estate in Sussex, the long-legged birds are sitting on three eggs which are due to hatch in June.

While white storks sometimes fly over the UK, the last chick to hatch on British soil is believed to have been born on Edinburgh's St Giles’ Cathedral in 1416.

Their return is part of an ambitious reintroduction programme to establish a stable wild population of storks by 2030.

Mary Davies, a species recovery officer with the Royal Society for the Protection of Birds (RSPB), told The Independent: “This news is great to hear and we’ll be watching with interest to see how the reintroduction develops."

The UK's top birds 2018 Show all 10 1 /10 The UK's top birds 2018 The UK's top birds 2018 10. Chaffinch Down one place on last year. Birdwatch has released this year's rankings for the most frequently spotted birds in the UK. Results were collected from 420,489 British birdspotters Getty The UK's top birds 2018 9. Long-tailed tit Up one place on last year Getty The UK's top birds 2018 8. Robin Redbreast Down one place on last year Getty The UK's top birds 2018 7. Great Tit Up one place on last year Getty The UK's top birds 2018 6. Goldfinch In the same place as last year Pierre Dalous The UK's top birds 2018 5. Woodpigeon In the same place as last year Getty The UK's top birds 2018 4. Blackbird Down one place on last year Getty The UK's top birds 2018 3. Blue tit Up one place on last year Getty The UK's top birds 2018 2. Starling In the same place as last year Getty The UK's top birds 2018 1. House sparrow In the same place as last year Getty

Author Isabella Tree, who owns the Knepp estate said that the parents-to-be were juveniles and their future was still uncertain.

“We watched them poking around with twigs and fighting over where to put a twig and we thought they were never going to build a nest, but it just grew like magic”, she told The Guardian. “Who knows if they will fledge chicks successfully but it’s lovely to see them back flying free.”

The reintroduction has been led by Cotswold Wildlife Park and Durrell Wildlife Conservation Trust.

The birds were brought over to Knepp from Warsaw Zoo and have been living in a six-acre predator-proof enclosure.

After the Second World War stork numbers dropped across Europe as farmers drained the marshy grasslands where the birds lived, and sprayed pesticides to poison the insects they ate.

However, in the past few decades the birds have already been successfully reintroduced in a number of European countries including France, Sweden, the Netherlands and Switzerland.

Support free-thinking journalism and attend Independent events

Stories of storks finding abandoned babies in caves and marshes and taking them to households all over the world have long been popularised in fables such as those of Hans Christian Andersen.