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Castle Blayney — Onomy

House — fortified house

Why this matters

Built or held by Sir Edward Blayney, an English captain stationed at Monaghan from 1602, Castle Blayney is remembered for its strategic position overlooking White Island and Muckno Lough, reflecting early 17th-century English military presence in the region.

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Overview

Castle Blayney — Onomy is recorded as House — fortified house in Monaghan. Located on a shelf towards the bottom of a NE-facing slope which overlooks White Island and the N end of Muckno Lough. Sir Edward Blayney was a captain in the English garrison at Monaghan town (MO009-060----) from 1602.

Who built and held it

The saved account records: By the end of the eighteenth century the castle was certainly a ruin, and a drawing by Francis Grose made in 1770 shows that it was T-shaped, of two storeys and attic with corner machicolations supported on continuous corbels in the Scottish fashion (Grose 1791, vol.

Attack, change and use

The saved account records: In 1642 the castle was occupied by rebels led by several of the local MacMahons who despoiled the estate and may have destroyed the castle irreparably as there is very little record of it thereafter.

What survives

The saved account records: In 1607 he received a grant of land at Ballylurgan, also known as Ballifort, which consisted of two ballybetaghs (or villages, each of sixteen tates or townlands) in Cremorne barony on condition that he built a fort there within four years (Lavery 1907, 31-2).

Why it mattered

Castle Blayney — Onomy matters because the source ties house — fortified house to this exact landscape and preserves evidence that a bare map name loses. The saved account adds: Located on a shelf towards the bottom of a NE-facing slope which overlooks White Island and the N end of Muckno Lough.

History checked 15 August 2026 against the named sources below.

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