Busbie Castle was situated in what is now known as Knockentiber (Scottish Gaelic: Cnoc an Tobair, hill of the well), a village in East Ayrshire, Parish of Kilmaurs, Scotland.

The castle overlooked the Carmel Glen and its Burn, which runs into the River Irvine, a mile or so to the south, after passing through the old Busbie Mill.

[3] The 1860s first edition of the OS shows that a pre-reformation chapel dedicated to the Virgin Mary was situated close to the site of Busbie Castle.

MacIntosh in 1894 refers to the castle as being "a prominent object in an otherwise monotonous landscape"[10] and describes the gun ports and arrow slits, also a sculptured cable which wound itself fantastically round the walls.

In 1547 Charles Mowat was again involved in a murder, this time with Lord Boyd; Sir Neil Montgomerie of Lainshaw being the victim.

[12] It was not all one way, for a brother of the Earl of Eglinton appears in court having provoked John Mowatt, Laird of Busby, and his servant, one Andrew Stevenston in the streets of Stewarton.

[13] The Mowat involved in the Montgomerie murder was in turn slain by William & Harrie (Sic) Stewart,[11] the two sons of Lord Ochiltree in 1577.

Alexander, the eldest son does not appear to inherit, instead James, his younger brother succeeded to the lands of Busbie.

Hugh Montgomerie, Ist Earl of Eglinton, had a charter on 3 February 1499 from James V of the £40 lands of old extent of Roberton in Cunninghame.

The present Busbie farm is marked on the older maps, e.g. 1860, as a mill, with a clear millrace or lade and a sluice.