- The Trench family at Woodlawn were one of a number of Trench families who came to prominence in county Galway in the 17th century. They were all descended from Frederick Trench who came to Ireland early in the 1600s. Strategic marriages into the Warburton and Power families led to the acquisition of more lands in East Galway. Much of the Woodlawn estate was originally Martin and Barnewall lands which were purchased by the Trenches in the early eighteenth century. Lord Ashtown is recorded as a non-resident proprietor in 1824. At the time of Griffith's Valuation he was one of the principal lessors in the parish of Ballymacward, barony of Kilconnell. In county Roscommon he held over a thousand acres in the parishes of Cam and Tisrara, barony of Athlone and in county Tipperary he held at least 21 townlands in the parishes of Ballingarry and Uskane, barony of Lower Ormond, inherited from the Sadleir family of Sopwell Hall. In the 1870s Lord Ashtown's estate in Galway amounted to over 8000 acres and he also held land in 7 other counties including county Waterford where he had purchased lands in the barony of Glenahiry from the Earl of Stadbrooke in the 1870s. These townlands remained in Trench ownership until purchased by the Land Commission in the 1930s.
At the time of Griffith's Valuation, Rev. Frederick Trench was leasing a house valued at £11 in the townland of Carrownamanagh, barony of Kilconnell, to Crawford Allen. The OS Name Books state that Mr. Birmingham acted as agent for the Trench estate.
Lands at Carrowbane, the property of William Wallace Trench, were offered for sale in the Landed Estates court in November 1863.
In 1852 Lord Ashtown married as his second wife Elizabeth Oliver Gascoigne, an heiress with large estates in county Limerick and Yorkshire. In the 1870s Lord Ashtown is recorded as the owner of 11,273 acres in county Limerick and 4,526 acres in county Tipperary. At the same time the Honourable Charles James Trench of Merrion Square, Dublin, owned 712 acres in county Tipperary. He was a brother of the 2nd Baron Ashtown. A nephew of the 1st Baron Ashtown Henry Trench of Glenmalyre, Queen's County (Laois) owned 699 acres in county Cork aand 671 acres in county Laois.
- William Trench of Cangort Park, Shinrone, county Offaly, born 1760, was the fourth son of Frederic Trench of Woodlawn, county Galway. He married Sarah Moore a granddaughter of Edward 5th Earl of Drogheda and they had 2 sons and 2 daughters. At the time of Griffith's Valuation the Trenches held some land in the parish of Croom, county Limerick. In 1836 Henry Trench, the second son of William and Sarah married a Bloomfield of Redwood, county Tipperary. In the 1870s Henry Trench of Cangort Park, Roscrea, owned 4,707 acres in county Tipperary, 2,113 acres in county Offaly, 1,926 acres in county Limerick, 1,581 acres in county Galway, 704 acres in county Clare and 432 acres in county Roscommon. His nephew the Reverend William Robert Trench of Liverpool owned 817 acres in county Tipperary.
Gascoigne/Trench (Castle Oliver)
- Richard Oliver of Castle Oliver, county Limerick, took the additional name of Gascoigne when he and his wife became the successors to the Gascoigne of Parlington estate in Yorkshire. Richard Oliver Gascoigne died in 1843 and was succeeded by his two daughters. In 1850 Mary Isabella married the Honourable Frederic Charles Trench, a first cousin of the 2nd Baron Ashtown. In 1852 her sister Elizabeth married Frederic Mason Trench, 2nd Baron Ashtown, of Woodlawn, county Galway, as his second wife. They had no children. Griffith's Valuation records the county Limerick estate of Elizabeth O. Gascoigne and her brother-in-law, Frederic Charles Trench, as situated mainly in the parish of Kilflyn, Kilfinnane and Particles but also in the parishes of Athneasy, Ballingarry, Darragh, Emlygrennan, Kilbreedy Major, and Knocklong, barony of Coshlea. In the 1870s Lord Ashtown owned over 11,000 acres in county Limerick while the Honourable F.C.T. Gascoigne of Parlington, Yorkshire, who had taken the additional name of Gascoigne, owned 7,766 acres in county Limerick. In June 1875 an estate on the Shannon estuary at Killocally, barony of Shanid, amounting to 727 acres was bought in trust for Colonel Gascoigne from Charles H. Minchin.