Henry Trench was the second son of William and Sarah Trench of Cangort Park, Shinrone, Co. Offaly. He married Georgina Mary Amelia Bloomfield on 22 October 1836 and had 8 children. By the 1870s Trench 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.