The first fortification on this lakeshore was a small castle built around 1546 by Dónal Ó Flaithbheartaigh - Donal O'Flaherty - one of several he raised across Connemara. Donal married Grace O'Malley (Gráinne Ní Mháille), the seaborne queen of the Mayo coast, which united the O'Flahertys with one of western Ireland's most formidable families and extended Donal's reach. The O'Flahertys ruled Connemara so completely that the gates of Galway city carried, into the seventeenth century, the inscription 'From the ferocious O'Flahertys, good Lord deliver us.' By the mid-1600s the castle had passed to the Martins, an Anglo-Norman family who were one of the fourteen Tribes of Galway. The Martins commissioned the present three-story country house in 1754 - originally not as a residence, but as an inn for travelers crossing Connemara.

The most famous Martin to live here was Richard Martin, born in 1754, who served as Member of Parliament for County Galway. He was a duelist of some reputation in his youth, fought several encounters over points of honor, and was credited with at least one death by sword. Then somewhere in middle life he became fascinated with the suffering of animals. He pushed through the British Parliament in 1822 the Ill Treatment of Cattle Act - the first national law anywhere in the world prohibiting cruelty to animals. Two years later, in a London coffee house in 1824, he co-founded the Society for the Prevention of Cruelty to Animals, which became the RSPCA in 1840. King George IV nicknamed him 'Humanity Dick.' He held court here at Ballynahinch through the 1820s and 1830s, entertaining Daniel O'Connell as a guest in 1843 - though by then Richard himself had died in Boulogne in 1834, his fortune lost in legal battles. The estate then passed through various hands and eventually came up for sale.

In 1924 a buyer arrived who nobody expected. Kumar Shri Ranjitsinhji Vibhaji - Ranji to the cricket world - was the Maharaja Jam Saheb of Nawanagar, ruler of an Indian princely state of about 400,000 people. He was also one of the greatest batsmen in cricket history, having played fifteen Test matches for England between 1896 and 1902 before returning to India to rule. He came to Ireland for the fishing on the Ballynahinch River and reportedly fell in love with the place. He bought the house, the estate, and the salmon and sea-trout fisheries from the Berridge family. He spent every year there until his death in 1933, lived as a working landowner, and provided substantial support to the Connemara region - investing in cottage industries, hiring more than fifty people on estate improvements. After his death the estate was sold to the McCormack family of Dublin, then in 1946 to the Irish Tourist Board, who turned it into a hotel.

Since 2014 the estate has been owned by Denis O'Brien and his wife Catherine, who refurbished the building and run it as a 48-bedroom hotel on 450 acres. The salmon fishery that drew Ranji is still here. The ancient woodland still surrounds the house. Benlettery still rises behind the building exactly as it did when Donal O'Flaherty first looked out at it. In July 1982 a darker chapter intruded: four top executives of the Florida-based Charter Company, guests of the then-owners, died in a helicopter crash while traveling from the hotel to Shannon Airport. The crash was reported in The New York Times. Today, walking the lakeshore in the morning, you would not guess at any of this - the duels, the animal-welfare laws, the Indian prince netting trout where the river meets the lake. A country house holds its stories quietly.