Rostellan Castle, County Cork is one of Ireland’s great lost houses, demolished less than 80 years ago and obliterated so completely that most visitors to the site would have no idea a substantial residence stood here for several centuries. The original building here is thought to have been constructed by a branch of the FitzGerald family; certainly by the mid-1560s the land it occupied had passed into the possession of Edmund FitzJohn FitzGerald, hereditary Dean of Cloyne. Knighted in 1602, he had a daughter Ellen who married Dermot O’Brien, fifth Baron Inchiquin and their eldest son, Murrough O’Brien, sixth Baron and first Earl of Inchiquin, would eventually come to own Rostellan. Remembered as Murchadh na dTóiteán (‘Murrough of the conflagrations’), he became notorious during the Confederate Wars from 1641 onwards for burning the houses, livestock and lands of his opponents, first the Catholic forces and then the Cromwellian army. In 1650 he left Ireland and moved to France where he joined the royal court in exile (and converted to Catholicism), returning to his country three years after the Restoration of the Monarchy in 1660 and thereafter living quietly on estates which had been restored to him by royal act. Although O’Brien’s family had historically been associated with County Clare, where he owned land, his preference in later years was to live at Rostellan, and this remained the case for subsequent generations until the mid-19th century. 

Following his death in 1674, the first earl’s estates, including Rostellan, were inherited by his eldest son William O’Brien who had not converted to Catholicism but remained loyal to the Protestant faith. A military man, he had lost an eye in 1660 when he and his father were captured by Algerian corsairs in 1660; 14 years later, he . became Governor of Tangier and Captain General of the King’s Forces there. Back in Ireland, in 1688 he declared his support for William of Orange, but then failed in an effort to raise troops in County Cork to oppose James II. In the aftermath of the Williamite Wars, William III appointed him Governor of Jamaica, where he died of disease in 1692. His heir, the third earl, also William O’Brien seems to have lived a quieter life, spending much of his time at Rostellan where he carried out various improvements, not least walling and damming the surrounding land to stop tidal incursions, since Rostellan sits on a promontory overlooking Lower Cork Harbour; in 1701 he advised Queen Anne that at considerable expense he had ‘prevented the tide from overflowing a parcel of land adjoining to his house at Rostellan, which would be an advantage to the harbour of Cork for small vessels and boats, if a quay was made there, and desiring her Majesty to grant to him and his heirs the said ground, containing about 150 acres.’ In 1710 it was noted that the earl ‘is now att Rostellan…as buesie as ever, building &c; there neaver will be an end. God help him…’ He died in 1719, and was succeeded by his eldest son, yet another William O’Brien, who, in 1720, founded the Water Club of Cork Harbour in 1720; among other offices, he also served as Governor of Clare for more than 30 years and was a Member of the Privy Council of Ireland from 1753. Although he spent much time in England, the fourth earl carried out extensive works on the dwelling house at Rostellan, perhaps incorporating the older building although this is unclear. Legend has it that he built the house on or near the site of an old graveyard, ordering that the tombstones be levelled, according to another version, thrown into the sea. In any case, a woman whose only son was buried there duly laid a curse on him, saying no son would succeed thereafter and that the family line would die out. Indeed, the fourth earl and his wife had four sons, but they all predeceased him and when he died in 1777, Rostellan was inherited by a nephew, Murrough O’Brien, created first Marquess of Thomond in 1800. He in turn had no male heir, so the estate once more passed to a nephew, who had four daughters but no son. Rostellan and the O’Brien lands accordingly passed to a brother, the third and last marquess who, despite being married three times, had no children. And so, on his death in 1855, the curse made over a century earlier came to pass, the line died out and Rostellan was sold. Over the following decades, the property changed hands on a number of occasions, finally being leased in 1930 to Cloyne China Clay Company. who mined clay there for export. That continued for  decade, after which the house stood empty until demolished by the Irish Army Corps of Engineers in 1944. 

Surviving photographs of Rostellan Castle show a three-storey house with a five-bay entrance front and three-sided bows at each corner. In the 19th century, a Gothic porch was added to the facade and to one side of the house a long, single-storey extension containing a Gothic-style chapel, ending in a squat round tower. All of this, as mentioned, has been entirely swept away, the area now occupied by pitches for a local GAA club. But along the shoreline are traces of the work undertaken by the fourth earl and his successors, not least a causeway with battlemented parapets and, at one point, the remains of a prow-like battery terrace, dating from 1727. Here were formerly set a number of canon, used for starting boat races (the earl having founded the Cork Water Club). Elsewhere along the same shoreline can be seen a rather stock Doric column with vermiculated plinth; originally this supported a lead statue by John van Nost the Younger of Admiral Edward Hawke. And further along are what survives of a battlemented round tower built as a tea house by the first marquess and named after the famous actress Sarah Siddons who he entertained there during one of her visits to Ireland. All in poor condition, these are all that remain of Rostellan Castle and its demesne; soon, like the house itself, they will disappear and with them the last memory of this place.