A butterfly that became extinct in England more than 40 years ago is being reintroduced in its former stronghold.
The chequered skipper was always scarce but became extinct in 1976 due to changes to woodland management.
Now 50 of the species, which can be found in Scotland, are being released in a secret location in Rockingham Forest, Northamptonshire, later.
Butterfly Conservation, which runs the project, said it was an "important milestone for conservation".
A decline in coppicing and maintaining long narrow tracks or rides, as well as a rise in conifer plantations which did not suit the butterfly led to its extinction in England.
But a project by Back from the Brink has enabled parts of the forest to be restored to conditions suitable for the chequered skipper.
It is hoped the renovated site will provide the habitat the chequered skipper needs to survive.
To minimise the impact on the population on any single donor site, 40 females and 10 males from up to five sites from Belgium were chosen.
Belgian chequered skippers were picked as their habitat is similar to that of Rockingham Forest.
The butterflies were taken via Eurostar across the Channel on Wednesday and transferred to Rockingham where they were placed in cages ahead of their release later.
'Charismatic little butterfly'
Reintroduction trials took place in the mid-1990s, with the data gathered helping to provide information ahead of the new reintroduction bid.
Dr Nigel Bourn, Butterfly Conservation director of Science, said: "Thursday is an important milestone for conservation in the UK.
"It is a privilege to help return this charismatic little butterfly to its former stronghold of Rockingham Forest.
"It has taken many years and a lot of hard work from many people to get to this point and I am very proud to be part of the team collecting these beautiful butterflies and returning them to England at last."
The project by wildlife charity Butterfly Conservation working with the Forestry Commission is part of a wider Back From The Brink programme.