This was a junior branch of the Lefroy family of Carrig-glass, county Longford. They were descended from the Reverend Henry Lefroy who married Dorothea O'Grady of Kilballyowen, county Clare in 1814. Their third son, Henry Maunsell, lived at Fern Hollow, Killaloe. He had a milling business in the town. Weir writes that a house named Cambrai was built at Knockyclovaun, parish of Killaloe, for Henry M. Lefroy's son in the early 20th century. Henry M. Lefroy is recorded as owning a mansion house at Knockyclovaun valued at £33 in 1906.