Prior to the arrival of the Normans, Ferns was the centre of power of the Uí Cinsealagh, ancestors of the MacMurchadas (known today as MacMurroughs). They rose to become Kings of Leinster in the 11th century, and constructed a large earth-and-timber fortification was first built where the castle now stands today.
Perhaps the most famous MacMurrough king was Diarmait MacMurchada. Diarmait was King of Leinster from around 1132. He was a significant supporter of Church reform, he was responsible for the foundation of a number of monasteries, abbeys and religious houses in the east and south-east, including Baltinglass Abbey in Wicklow, and Killeshin Church in Laois, and All Hallows in Dublin. Diarmait became embroiled in a bloody feud with Tigearnán Ua Ruairc, the King of Breifne (roughly, the modern counties of Leitrim, Cavan and parts of Meath), this was exacerbated when Diarmait abducted Ua Ruairc’s wife Derbforgaill during a raid, as recorded in the Annals of Tigernach:
A hosting by Toirdhealbhach Ó Conchobhair and Diarmaid Mac Murchadha against Tighearnán Ó Ruairc, and they burned Bun Cuilinn and inflicted a defeat on Tighearnán, and made the son of Giolla Bruide Ó Ruairc king of Conmaicne, and he got the lordship of them all. And Diarmaid mac Murchadh, king of Leinster, forcibly carried off out of Meath the wife of Ó Ruairc, that is, Derbhfhorgaill, daughter of Murchadh, with her wealth.
Annals of Tigernach: T1152.6.
The ill-feeling continued for well over a decade, and Ua Ruairc burned Diarmait’s fort at Ferns in 1166. When the High King of Ireland, Ruaidrí Ua Conchobair supported Ua Ruairc by banishing Dairmait, he fled Ireland. The Norman King of England, Henry II, allowed him to seek support amongst his barons and knights. In South Wales he received the support of Richard de Clare, Earl of Pembroke, known as Strongbow. The two men came to terms, with the understanding that Strongbow and his Norman forces would help Diarmait to defeat his enemies, in return for Strongbow being named as Diarmait’s successor as Lord of Leinster and being given his daughter Aoife’s hand in marriage. After the Normans invaded in 1169, both men kept their word. Though Diarmait died soon after in 1171.
The story of Ferns Castle continues below the gallery.