Source: Johnston, Alexander, Jr., Genealogical account of the family of
Johnston of that ilk, formerly of Caskieben, in the Shire of Aberdeen, and of
its principal branches. Edinburgh, 1832.
Alexander de Johnston - who in the reign of James II, got his lands of
Caskiben, which were formerly held of the Earls of Mar as superiors, erected
into a free barony, to be called the Barony of Johnston in all time coming, by a
decreet of the Lords, which was afterwards ratified and confirmed by King James
IV on 21st February 1502; and from thenceforth, the family were designed of that
Ilk. He married Agnes, daughter of Alexander Gloster of that Ilk, and of Glack,
a powerful baron in the district of the Garioch, in the shire of Aberdeen; and
by this lady had a family of four sons 1) William 2) also named William who
married a daughter of John Kieth of Auquhorsk of whom the Johnston's of
Cayesmill came -the other two sons died without succession. There is contained
in the records of the Great Seal a charter "Alexandro Johnestoun de eodem
et Agnetti Gloster, Sponsae suae, terrarum forrestae de Cordiss" 22nd
January 1498. He was succeeded by his eldest son.