The Mantua estate in county Roscommon came into Grace ownership in the 18th century through the marriage of Oliver Grace, a member of the Grace family of Gracefield, Queen's county (county Laois) and Mary, daughter and heiress of John Dowell of Mantua. Oliver Dowell John Grace was one of the principal lessors in the parish of Kilcolagh, barony of Frenchpark and in the parish of Shankill, barony of Roscommon, at the time of Griffith's Valuation. In 1828 he was a member of the Grand Panel of county Roscommon. The family seat was at Mantua, near Elphin. The estate amounted to over 3000 acres in the 1870s. It passed by marriage to the Bowen family of county Donegal at the end of the 19th century.