Tullymongan Hill in Cavan town was the site of a castle belonging to the O’Reilly kings of East Breifne. It was used as their chief residence from the 14th to early 17th centuries.¹

Breifne was divided into two opposing kingdom in AD1256 following the Battle of Magh Slécht between the O’Rourkes and the O’Reillys. The O’Rourkes were victorious on this occasion but couldn’t consolidate their rule, so the kingdom remained split from here on after. The O’Rourkes ruled West Breifne from Dromahair Castle, Leitrim, while the O’Reillys originally based themselves at Cloughoughter Castle in central Cavan. Cloughoughter was built by the de Lacys but fell into O’Reilly hands not long after its construction. In the 14th century the O’Reillys moved to a new site on Tullymongan hill in modern Cavan town.²

The castle at Tullymongan first appears in annals as being destroyed by the Earl of Ormond in 1427 and the town burned.³ The town also suffered the same fate two years⁴ later during the Clanmahon rebellion against the O’Reilly chief, Eoin na Feosaige. In 1468 the Earl of Worcester burned both the castle and the monastery,⁵ and in 1514 the castle was burnt yet again – this time by the Earl of Kildare in response to attacks on the Pale by the men of Breifne. Fourteen O’Reilly chieftains were killed on this occasion.⁶ The castle is depicted on a map from 1591 and appears as a large square building with a door in the west wall, an outside staircase and turrets rising above the roof level. There was also a bawn (courtyard) enclosing several buildings.⁷

Tullymongan was only one of the numerous castles scattered throughout East Breifne but was the only one which developed a highly-organised commercial market. Cavan and Longford are the only Irish towns to be classified as Gaelic market towns,⁸ most other towns or cities have Norse, Norman or later origins. Cavan town sprung up around Tullymongan and developed into trading centre that provided a sustainable source of revenue for the O’Reillys. Such was the wealth in the town that the O’Reillys even minted their own coins known as ‘O’Reillie’s money’.⁹

The fact that the castle of this size was built during the 14th century is quite impressive in itself. Due to the Great European Famine, the Bruce invasions and the bubonic plague, there was generally a steep decline in castle building during this period.¹⁰ The castle lasted until the Plantation of Ulster in the 17th century, when it was then demolished and some of the stones used to build a nearby school. Others were used in the construction of a strong house for a Servitor of the Plantation.¹¹

References

---

1. O. Davies, ‘The Castles of Co. Cavan: Part II’ in Ulster Journal of Archaeology, Third Series, Vol. 11 (1948), pp. 88-90
2. Jonathan Cherry, ‘Colonial appropriation of Gaelic urban space: creating the first Ulster plantation town’ in Irish Geography Journal Vol. 40, Issue 2 (2007) p. 115
3. Annals of the Four Masters, M1427.15, Available at https://celt.ucc.ie (Jun. 15, 2022)
4. Annals of the Four Masters, M1429.5, Available at https://celt.ucc.ie (Jun. 15, 2022)
5. Annals of the Four Masters, M1468.25, Available at https://celt.ucc.ie (Jun. 15, 2022)
6. Annals of the Four Masters, M1514.6, Available at https://celt.ucc.ie (Jun. 15, 2022)
7. Map of Cavan town from 1591, reproduced in Philip O’Connell’s ‘The Diocese of Kilmore’ (Dublin 1937), p. 301
8. A. Simms and K. Simms, ‘The origins of principal towns’ cited in Jonathan Cherry, ‘Colonial appropriation of Gaelic urban space: creating the first Ulster plantation town’ in Irish Geography Vol. 40, No. 2 (2007) pp. 112-127
9. Cherry, ‘Colonial appropriation of Gaelic urban space’, pp. 112-127
10. T.B. Barry, The Archaeology of Medieval Ireland (London and New York, 1987), p. 68
11. O. Davies, ‘The Castles of Co. Cavan: Part II’ in Ulster Journal of Archaeology, Third Series, Vol. 11 (1948), pp. 90, 101

Previous Page | Loch Gabhair