A tarpan mare and foal in their new home in Bulgaria.
The tarpans have been released near Sbor, in the municipality of Krumovgrad, in the expectation their grazing will improve the natural environment.
They were imported from a free-living population in the Netherlands in a project that received funding from the Dutch Postcode Lottery.
In the first year of the Bulgarian experiment, wildlife experts will keep the tarpans fenced for appropriate habituation to the Rhodopian wilderness.
Once the horses are acclimatised, they will be released into the wild.
Their role in Eastern Rhodopi will be the same as in ancient times - to graze the wild vegetation and support a natural ecosystem.
Wild tarpans have a reputation for being tough and easily adapted to the harsh conditions of semi-open wilderness landscapes.
Tarpan (Equus ferus ferus), also known as the Eurasian wild horse, is an extinct subspecies of the wild horse.
The tarpan is a prehistoric wild horse type that ranged from Southern France and Spain east to central Russia.
There are cave drawings of what are considered to be tarpans in France, Spain and Scandinavia, as well as artifacts from southern Russia, where Scythian nomads domesticated a horse of this type around 3000 BC.
Also, in Bulgaria, paleaontologists found tarpan bones, proving this wild horse once lived there.
Tarpans became extinct in the wild between 1875 and 1890, when the last known wild mare was accidentally killed in Russia during an attempt to capture it.
The last captive Tarpan died in 1909 in a Russian zoo.
Beginning in the 1930s, several attempts were initiated to recreate a look-a-like tarpan through selective breeding with domestic breeds which allegedly retained much Tarpan DNA in their genome.
The look-a-like Tarpan reintroduced in Bulgaria is also known as the konik (Polish for 'little horse'). This breed originated from Polish tarpan re-creation projects.
In 1936, Tadeuzs Vetulani was fascinated by the exterior resemblance of some specific primitive farmer's horses and the extinct tarpan.
He started a breeding programme with 35 such horses from an area where a century earlier the last tarpans were captured in the wild and distributed to farmers.
In some countries, such as in the Netherlands, the konik was reintroduced to nature parks successfully about 30 years ago.
Tarpans, which stand about 137-149cm tall and weigh 400-500kg, are robust horses with well developed social behaviours.
A social herd of horses helps provide protection against predators - wolves.
The total number of tarpans in the world at this moment is estimated at 4000, almost half of them in the Netherlands.
In 2010, 21 Dutch tarpans were reintroduced to the wild in Latvia. In previous years, tarpans from Holland have gone to wilderness areas in England, France, Belgium and Germany.
Before implementing the reintrodution of the Tarpans in Bulgaria, the team explored the Eastern Rhodopes for a suitable area and checked Bulgarian legislation and official requirements.
The team organised meetings with local authorities and local people, because local co-operation was necessary in such unique experiment.
Bringing tarpans to the Eastern Rhodopes is part of the wilderness restoration plans of the five-year New Thracian Gold project, to develop the area environmentally.
Last year, semi-wild Karakachan horses were reintroduced in the area of Chernichino. Red deer reintroduction is also planned.
Ecologists believe the reintroduction of ancient herbivores to the wild improves the biodiversity and makes the ecosystems more complete.
Free-ranging wild horses are rare in Europe and unique in Bulgaria.
The combination of beautiful landscapes, rich biodiversity and wild tarpans is a potential key factor in boosting eco tourism as a new economic driver in the Eastern Rhodopes. Eco tourism helps to support the Eastern Rhodopes as a prosperous and attractive place to live and work.