The Friarstown estate was held on lease by the Johnston family from the Earl of Milltown though Friarstown House seems to have been leased to others. Aghacashel was leased by the Johnston family from the Blachford estate of Lisnover in county Cavan. Members of the Johnston family of Aghacashel and Friarstown served as High Sheriffs of Leitrim between 1701-1812. In 1802 McParlan recorded Robert Johnston of Ahacashel and John Johnston of Friarstown on his list of "resident gentlemen of property". In 1851 lands, the property of John and Thomas Johnston, at Killaleen, barony of Dromahaire were offered for sale in the Encumbered Estates Court. Later, in June 1855, properties in the baronies of Carrigallen and Leitrim, the estate of Joseph & Robert Johnston, were offered for sale. Jane Page, the administratrix of John Johnston, offered for sale lands in the barony of Dromahaire, in the Encumbered Estates Court in February 1857. In December 1858 demesne lands at Friarstown as well as lands in the baronies of Tirerrill and Dromahaire were offered for sale by John William Johnston.
In May 1858 the house and demesne at Aghacashel were offered for sale by William Blachford and Charles Hamilton. The documents indicate that the original lease, in 1744, was between Rev. John Blachford and George Johnston. In May 1862 John Johnston offered for sale over 1700 acres in the parish of Killarga in the Landed Estates Court. The observations indicate that these lands were, until the end of the seventeenth century, the property of the O'Rorke clan. In the eighteenth century they were acquired by Patrick Cullen who later sold a portion to the Johnston estate. The Irish Times reports that some of the lots in this sale were purchased by the owner while others were purchased, in trust, by Mr. Palmer. In November 1865, January and July 1866 John Johnston again offered for sale lands at Friarstown. The house at Aghacashel and over 200 acres of untenanted land had become the property of Thomas Guckian by 1906. Possibly connected with the Johnstons of Killannin.