Until the middle of the 19th Century the ponies were found throughout the islands and used by crofters ponies, undertaking everyday tasks like carrying peat and seaweed in basket work, pulling carts, harrowing and even taking children to school.
Some 40 years ago though the picture for the small and hardy pony look bleak, with only scores left in existence.
Dwindling to a dangerously low number of 20 mares and a single stallion -- called Eric -- a rescue attempt was launched by a band on islanders in the 1970s.
Now, with the help of Eric, 420 exist worldwide. Howver the breed is still one of Europe's most threatened horses and is still listed as critically endangered by the Rare Breeds Survival Trust.
Two registries for the breed have been established, the locally-based Comann Each nan Eilean (CEnE), formed in 1972, and the Eriskay Pony Society (EPS), set up in 1986.
Lady Liz Sanderson, Eriskay breeder and president of the EPS, said: "We mustn't lose the breed. It's part of Scottish history and they are so versatile."
Ruth McMinn, EPS chair, also said the remoteness of the islands had helped keep the breed pure.
She added: "It would be such a tragedy if this breed was lost as it is a native Scottish pony with a very important cultural heritage."
In addition to domesticated ponies, there is a small herd of Eriskay ponies living wild on the Holy Isle.
The predominant colour of the pony is grey with the occasional black or bay and in winter a dense waterproof coat enables them to live out in the harshest conditions.
They are also said to enjoy human company and are immensely strong for their size.