Tower houses in Britain and Ireland

The tower house (Irish: caisleán) appeared in Britain and Ireland starting from the High Middle Ages. Such buildings were constructed in the wilder parts of Britain and Ireland, particularly in Scotland, and throughout Ireland, until at least up to the 17th century. The remains of such structures are dotted around the Irish and Scottish countryside, with a particular concentration in the Scottish Borders where they include peel towers and bastle houses. Some are still intact and even inhabited today, while others stand as ruined shells.

Tower houses are often called castles, and despite their characteristic compact footprint size, they are formidable habitations and there is no clear distinction between a castle and a tower house. In Scotland a classification system has been widely accepted based on ground plan, such as the L Plan Castle style, one example being the original layout (prior to enlargement) of Muchalls Castle in Scotland.

The few surviving round Scottish Iron Age towers known as brochs are often compared to tower houses, having mural passages and a basebatter, (a thickening of the wall that slopes obliquely, intended to prevent the use of a battering ram) although the entrances to Brochs are far less ostentatious.

In Ireland, there are well over 2,000 tower houses extant and some estimate that there were as many as 8,000 built during the Middle Ages. The construction of the majority of tower houses is thought to have commenced in the early 15th century AD and lasted until the mid-seventeenth century. After 1580 many lords built fortified houses and stronghouses although tower houses continued to be built until the guns of the Cromwellians rendered such private defenses more or less obsolete. It is possible that many were built after King Henry VI of England introduced a building subsidy of £10 in 1429 to every man in the Pale who wished to build a castle within 10 years, Ireland being under English control at the time (Statute Rolls of the Parliament of Ireland, Reign of Henry VI, pp 33-5). Recent studies, however, have undermined the significance of this grant, demonstrating that there were many similar grants at different times and in different areas.

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