They were once lords of the forest, hulking great beasts that provided sport for kings and counts as they wandered the wilds of Bulgaria.

Now, the bison is back, with conservationists in the Balkan country celebrating the birth of the first bison calf in the wild for more than eight centuries.

A small herd of seven bison were released into a nature reserve in the Rhodope Mountains of Bulgaria this summer, with a female recently giving birth to a calf.

“This is the first wild bison born south of the Danube since the Middle Ages,” Hristo Hristov, a member of the reintroduction project, told The Telegraph.

The bison calf is the first to be born in the wild south of the Danube for around 800 years credit: Dessy Kostadinova/Rewilding Rhodopes.

“We are not sure exactly when the calf was born because the mother gave birth in one of the wildest, most secretive parts of the reserve, a valley that is very hard to reach.

“It’s a hugely important event for us. We are proud that after eight centuries or more, the first bison calf has been born in the wild in Bulgaria.”

Conservationists have named the calf Nadezhda, meaning “hope” in Bulgarian. The animal is “a symbol of hope for a wilder and more biodiverse Rhodope Mountains,” said Mr Hristov.

The return of the bison has been pioneered by a conservation organisation called Rewilding Europe, which is reintroducing animals such as chamois and wild horses to wilderness areas across the continent.

Eurasian lynx are among the animals that conservationists would like to see reintroduced credit: Bruno Mathieu/Biosphoto

The objective is two-fold – to encourage the growth of wildlife-watching tourism in rural areas where unemployment is often high, and to re-establish animals that once played key roles in the ecology of the forest.

Bison, for instance, play an important part in creating meadows and grasslands by browsing on scrub and forest.

As Europe’s largest land animal, there is not much they cannot bulldoze through, and that creates habitats for a wide range of plants, animals and insects.

The long-term aim is to have a herd of up to 50 bison in the Rhodope Mountains, a rugged region on Bulgaria’s southern border with Greece.

The project has only been possible because local communities are supportive of the bisons’ return, said Dessy Kostadinova from Rewilding Rhodopes, part of the broader Rewilding Europe organisation.

A small herd of wild bison is roaming a nature reserve in the Rhodope Mountains in Bulgaria credit: Dessy Kostadinova/Rewilding Europe

“The locals are proud that bison have returned to this part of Bulgaria,” she said. “At the beginning they were a little bit scared, asking if the bison were dangerous. But there is no danger at all, as long as you give the animals some space and observe them from a distance.”

There are plenty of wolves in the area but so far, they are not preying on the new arrivals.

“The bison are big, and the wolves have not seen them for centuries, so for now they are not a problem,” said Mr Hristov.

Bison have also been reintroduced in the Carpathian Mountains of neighbouring Romania in a project that started five years ago, and there are also herds in the Netherlands and Germany.

In total, there are now around 3,500 bison living in wild or semi-wild environments across Europe.

European bison, which stand at 6ft tall and can weigh up to 2,000lb, were hunted to extinction by the start of the 20th century.

A few survived in captivity and were eventually reintroduced into the Bialowieza Forest in Poland and Belarus, which is now home to the largest herd in the world.

Compared to its trans-Atlantic cousin, the American buffalo, the European bison is longer-legged and prefers to live in woodland, rather than open plains.