This type of structure is somewhat common in Ireland, but the only Scottish examples are those at Brechin, Abernethy in Perthshire, and Egilshay in the Orkneys.
William the Conqueror answered this attack by marching into Scotland in 1072, whereupon Malcolm made peace with the English king at Abernethy and "was his man."
Besides the dozen forts on the wall, one or two outposts may have been held at Ardoch and Abernethy along the natural route which runs by Stirling and Perth to the lowlands of the east coast.
At the same time the Roman forts at Ardoch, north of Dunblane, Carpow near Abernethy, and perhaps one or two more, were occupied.
In 1072 William marched north and took a disputed homage of Malcolm at Abernethy, receiving as hostage the king's eldest son (by his first wife, Ingebiorge), named Duncan.
In 1091 William Rufus renewed the treaty of Abernethy with Malcolm and fortified Carlisle, thereby cutting Malcolm off from Cumberland; Malcolm was summoned to meet Rufus at Gloucester; he went, but declined to accept the jurisdiction of the Anglo-Norman peers, or to " do right" to Rufus, except on the frontier of the two realms, wherever he may have supposed that frontier to be.
The chief houses in Scotland were at St Andrews, Dunkeld, Lochleven, Monymusk in Aberdeenshire, Abernethy and Brechin.
In the same fashion the Culdees of Monymusk, originally perhaps a colony from St Andrews, became Canons Regular of the Augustinian order early in the 13th century, and those of Abernethy in 1273.
At Brechin, famous like Abernethy for its round tower, the Culdee prior and his monks helped to form the chapter of the diocese founded by David I.
Next year a movement against subscription was begun in the General Synod of Ulster, culminating (1725) in the placing of the advocates of non-subscription, headed by John Abernethy, D.D., of Antrim, into a presbytery by themselves.
The earlier letters of this correspondence show how rapidly he rose to distinction in a field where success was difficult, as it was already occupied by such men as John Abernethy, Sir Astley Cooper and Henry Cline.