- This family are descended from William Penn founder of the state of Pennsylvania, United States of America. William Penn of Shanagarry, county Cork had a daughter and heiress Christiana Gulielma Penn who married Peter Gaskell of Bath. They were the parents of Peter Gaskell of Bath and Philadelphia who assumed the additional name of Penn in 1824. His second son Thomas of Ballymaloe, county Cork and Pennsylvania died in 1848 and was succeeded by his brother Peter Penn Gaskell. At the time of Griffith's Valuation the Penn Gaskell estate was located mainly in the parish of Kilmahon but also in the parishes of Bohillane and Cloyne, barony of Imokilly. In the 1870s Peter Penn Gaskell of America owned 1,913 acres in county Cork.
- A family settled in the vicinity of Carrigtuohill near Cork city from the mid 17th century. Alexander Durdin of Shanagarry, born 1712, married four times. His third wife was Anne Penn widow of William Penn, grandson of the founder of Pennsylvania and Sir Bernard Burke states that through her Alexander came to possess estates in Ireland and America. His fourth wife was Margaret daughter of Warham St Leger. Warham Durdin was the eldest son of the fourth marriage. He lived at Sunville, Dromadda and Midleton Lodge and by his wife Anne Garde had 10 children. Their son Thomas Durdin of Shanagarry Castle held land in the parishes of Ballintemple, Ballyoughtera, Cloyne, Kilmahon, barony of Imokilly at the time of Griffith's Valuation. In June 1855 the fee simple estate of Thomas Garde Durdin amounting to 1,650 acres in the barony of Imokilly was advertised for sale. The representatives of Thomas Durdin, Shanagarry, owned 935 acres in the 1870s. Members of this family also owned land in county Carlow.
- Sir William Penn, an English admiral, was granted the castle and manor of Macroom, county Cork, in the mid 17th century. At the restoration of the monarchy he lost these lands and received an estate at Shangarry in 1667 in compensation. This estate amounted to 7,282 acres in the barony of Imokily and 4,859 acres in the barony of Ibane. His son William Penn, a Quaker, founded the state of Pennsylvania in America after spending some time in county Cork in the late 1660s. The Penn estate in county Cork passed into the possession of the Gaskell and Durdin families.
- Thomas Dawson was created Baron Cremorne in 1797. In the 18th century he owned an estate in county Waterford, as well as estates in counties Monaghan and Armagh. He was succeeded in 1813 by his great nephew, Richard Thomas Dawson and his son, also named Richard Dawson, 3rd Baron Cremorne, was created Earl of Dartrey in 1866. The Dawsons were settled in county Monaghan from the early 18th century. They had connections through marriage with the Veseys, the Penns, the Whaleys and the O'Briens of Dromoland, county Clare. In 1841 the 1st Earl of Dartrey married Augusta, daugher of Edward and Lady Mary Stanley. At the time of Griffith's Valuation Lord Cremorne held three townlands in the parish of Lorrha, barony of Lower Ormond, county Tipperary. He was also among the principal lessors in the parishes of Colligan, Dungarvan and Fews, barony of Decies without Drum, county Waterford. Castle Dawson, county Monaghan, was the seat of this family.