The first St Johns to come to Ireland were of Anglo-Norman origin and settled here in the 13th century, many of them in what is now County Tipperary. It is, therefore, not surprising to find one of the places in which they established themselves came to be called St Johnstown, or that this now contains the remains of what was once a substantial tower house: St Johnstown Castle.
St Johnstown Castle dates from some time in the later 15th/early 16th century when many such edifices were being constructed. While the precise year remains unknown, the man responsible for commissioning the building does not, since inserted above the main entrance on the east side of the building is a large carved panel, the centre of which is occupied by a shield divided into quarters: two sets of six scallop shells diagonally face two sets of three fishes. Around the shield, and onto the surrounding wall, raised lettering carries the following inscription ‘Robert De Sero Johe Ons De Cualeagh, Lismoynan, Scadanstown Et socius Illuis Plebis Fecit.’ (Robert St John, Lord of Cooleagh, Lismoynan, Scadanstown, and a friend of his people had me built). Of rough-hewn limestone from a local quarry, the now-roofless, five-storey tower house is some 60 feet high and measures 35 feet from east to west, and a little over 29 feet from north to south. There are chimney stacks on the north and south sides, and substantial bartizans wrapping around the north-east and south-west corners. While the lower floors have only narrow slits to let in light, more substantial window openings exist on the upper levels
It would appear that at some date during the upheavals of the 17th century the St Johns were displaced from this property, which then passed into other hands; by the second half of the 18th century, it was owned by one Matthew Jacob, whose only daughter and heiress, Anne, in 1782 married the M.P. Richard Pennefather of New Park. St Johnstown Castle was subsequently inherited by one of the couple’s sons, Matthew Pennefather but by 1837 Samuel Lewis could refer to it as being ‘the property of James Millet Esq who has a modern house in its immediate vicinity.’ Millet died in 1850, after which there does not seem to be much information about what happened to the place. But the ‘modern house’ mentioned by Lewis is of interest, since it looks to be a late 18th/early 19th century building with pretensions towards grandeur: lying to the immediate north of the tower house, it is of seven bays and two storeys with one bay, single-storey wings to either side. Although the site is now accessed via the yard behind the house, originally there was a drive that swept through the parkland to the south and then arrived at the main, east-facing main entrance, with a fine carriage arch leading to the aforementioned yard on one side. While the tower house has long since been abandoned, the same is not the case for the later building, albeit this now rather dilapidated. A fascinating example of a site that, while undergoing alterations, has remained in use since the Middle Ages.