Beavers have been reintroduced to England for the first time in 500 years.
Six European beavers have been released at Lower Mill Estate near South Cerney, and are destined to be the first to roam wild in England for centuries.
Although the animals will be confined to a 500-acre site to start with, it is hoped the fences can be removed once the beavers are settled.
The six adults were caught in Bavaria and had been held in quarantine.
If the pioneering scheme is successful, it is hoped beavers can once again thrive in the British countryside.
Hunted to extinction
The beaver was hunted almost to extinction for its fur and the pain-relieving properties of its anal gland secretions.
Whereas the American beaver can be destructive, environmentalists say the European species should be a force for good in the countryside.
The animals will be confined to a 500-acre site to begin with
It is herbivorous so it should not deplete fish stocks in rivers and the beavers could also help keep waterways clear of debris.
This is the second attempt to re-introduce beavers to England - a previous attempt in 2001 in Kent ran into difficulties with the animals failing to breed.
The release of the animals is seen as the first step in a programme to re-introduce the Eurasian beaver into wetlands across the area.
The beavers were released into purpose-built straw lodges, with an access chute into the lake which will become their home.
Speaking at the release, land owner Jeremy Paxton said: "We now just need to leave them alone and let them get on with a bit of breeding."
A Defra spokeswoman said the release of a non-native species would be subject to a scientific environmental assessment and licensed by Defra.