- The MacDermots were the original hereditary owners of the lands in Coolavin, hence the family title MacDermot of Coolavin. In the 17th century they lost much of their lands but always maintained a presence in the area. In the early 19th century they held a house and demesne at Coolavin. McParlan recorded "Doctor McDermott, son and heir of the late Prince of Coolavin, ........resides in the family mansion". At the time of Griffith's Valuation, Charles McDermott was the lessor of most of the townland of Monasteraden, barony of Coolavin and was also leasing lands in the barony of Tirerill. Portion of this property, including the house and demesne at Coolavin, was offered for sale in the Encumbered Estates Court in 1852. Lands in the barony of Tirerrill were offered for sale in March 1860. In the 1870s Charles J. McDermott owned almost 800 acres in county Sligo while Roderick and Thomas McDermott owned another 800.
- Thomas Deane, a merchant, was granted over 1,500 acres mainly in the baronies of Clare and Dunmore, county Galway, including Castlemoyle and Toghermore, but also in the barony of Kilmaine, county Mayo, by patent dated 2 June 1677. Stephen Deane was granted lands in the baronies of Loughrea, Moycullen and Athenry, county Galway and in the barony of Carra, county Mayo in May 1677. The Deanes held land in the parish of Annaghdown, barony of Clare, county Galway, in the late 18th century and also in the town of Galway. By the end of the 18th century Ambrose Deane was bankrupt and in 1790 sold Toghermore to John Henry of Dublin and Castlemoyle was sold to Valentine O'Connor in 1796. Ambrose Deane died intestate in 1792 and one of his sisters succeeded to the Deane estate of Balrobuck, parish of Annaghdown. She was married to Dominick Skerrett of Ballinduff. At the time of Griffith's Valuation Edward H. Deane held land in the parish of Cummer, barony of Clare. In the 19th century Edward Deane was agent to Christopher McManus of Barleyhill and leased land in the parish of Killedan, barony of Gallen, county Mayo. The Deanes appear to have lent money to the McManuses and in the early 1850s Edward Deane went to America to escape his creditors. He was married to Esmy O'Flaherty of Lisdonagh, near Headford, county Galway. A brother and sister of Edward Deane's married members of the McDermott family of Coolavin, county Sligo.
- This estate was centred around the house at Alderford, near Ballyfarnon, in County Roscommon. It included some land in the parish of Tuam, barony of Dunmore, county Galway in the mid 1850s. MacDermott lands in the parish of Kiltrustan, barony and county of Roscommon were offered for sale in January 1852. The MacDermottroe family were connected with the MacDermot family of Coolavin. In the 1870s Thomas Charles McDermott owned 2,505 acres in county Roscommon. See http://www.macdermot.com/library/Origins.html for further details.