Guinness is born on November 1, 1840 at St. Anne’s, Raheny, near Dublin, the eldest son of Sir Benjamin Guinness, 1st Baronet, and elder brother of Edward Guinness, 1st Earl of Iveagh. He is the great-grandson of Arthur Guinness. He is educated at Eton College and Trinity College Dublin and, in 1868, succeeds his father as second Baronet.
In the 1868 United Kingdom general election Guinness is elected Conservative Member of Parliament for Dublin City, a seat he holds for only a year. His election is voided because of his election agent’s unlawful efforts, which the court finds were unknown to him. He is re-elected the following year in the 1874 United Kingdom general election.
A supporter of Benjamin Disraeli‘s one-nation conservatism, Guinness’s politics are typical of “constructive unionism,” the belief that the union between Ireland and Britain should be more beneficial to the people of Ireland after centuries of difficulties. In 1872 he is a sponsor of the “Irish Exhibition” at Earlsfort Terrace in Dublin, which is arranged to promote Irish trade. Correcting a mistake about the exhibition in the Freeman’s Journal leads to a death threat from a religious extremist, which he does not report to the police. In the 1890s he supports the Irish Unionist Alliance.
After withdrawing from the Guinness company in 1876, when he sells his half-share to his brother Edward for £600,000, Guinness is in 1880 raised to the peerage as Baron Ardilaun, of Ashford in County Galway. His home there is at Ashford Castle on Lough Corrib, and his title derives from the Gaelic Ard Oileáin, a ‘high island’ on the lake.
Between 1852 and 1859, Guinness’s father acquires several large Connacht estates that are up for sale. With these purchases, he becomes landlord to 670 tenants. With his father’s death in 1868, Guinness continues in his father’s footsteps, purchasing vast swaths of Galway. When his acquisitions are combined with those of his father, total acreage for the Ashford estate is 33,298 acres, with Guinness owning most of County Galway between Maam (Maum) Bridge and Lough Mask.
Like many in the Guinness family, Guinness is a generous philanthropist, devoting himself to a number of public causes, including the restoration of Marsh’s Library in Dublin and the extension of the city’s Coombe Lying-in Hospital. In buying and keeping intact the estate around Muckross House in 1899, he assists the movement to preserve the lake and mountain landscape around Killarney, now a major tourist destination.
In his best-known achievement, Guinness purchases, landscapes, and donates to the capital, the central public park of St. Stephen’s Green, where his statue commissioned by the city can be seen opposite the Royal College of Surgeons in Ireland. To do so he sponsors a private bill that is passed as the Saint Stephen’s Green (Dublin) Act 1877, and after the landscaping it is formally opened to the public on July 27, 1880. It has been maintained since then by the Commissioners of Public Works in Ireland, now the Office of Public Works.
Guinness dies on January 20, 1915 at his home at St. Anne’s, Raheny, and is buried at All Saints Church, Raheny, whose construction he had sponsored. Those present at the funeral include representatives of the Royal Dublin Society, of which he is president for many years, the Royal Horticultural Society of Ireland, the Irish Unionist Alliance, and the Primrose League. His barony becomes extinct at his death, but the baronetcy devolves upon his nephew Algernon.