of his older brother, Énna Mac Murchada, Diarmait unexpectedly became King of Leinster. This was opposed by the then High King of Ireland, Toirdelbach Ua Conchobair (Turlough O'Conor) who feared (rightly) that Mac Murchada would become a rival. Toirdelbach sent one of his allied kings, Tigernán Ua Ruairc (Tiernan O'Rourke) to conquer Leinster and oust the young Mac Murchada. Ua Ruairc went on a brutal campaign slaughtering the livestock of Leinster and thereby trying to starve the province's residents. Mac Murchada was ousted from his throne, but was able to regain it with the help of the Leinster clans in 1132. Afterwards followed two decades of uneasy peace between Ua Conchobair and Diarmait. In 1152 he even assisted the High King to raid the land of Ua Ruairc who had by then become a renegade. Mac Murchada also is said to have abducted Ua Ruairc's wife Derbforgaill (English: Dervorgilla) along with all her furniture and goods, with the aid of Derbforgaill's brother, a future pretender to the kingship of Meath. Other sources say that Derbforgaill was not an unwilling prisoner and that she remained in Ferns with Mac Murchada in comfort for a number of years. Her advanced age indicates that she may have been a refugee or a hostage; in any case, she was under his protection. Whatever the reality, the "abduction" was given as a further reason or excuse for enmity between the two kings. Church builder As king of Leinster, in the years 1140–70 Diarmait commissioned the Irish Romanesque buildings of: Baltinglass Abbey St Saviour's Priory Ferns Abbey Killeshin Church He sponsored convents (nunneries) at Dublin (St Mary's, 1146), and around 1151 two more at Aghade, County Carlow and at Kilculliheen near Waterford city. The abbey of St. Mary Del Hogge in Dublin was named after the Hoggen Green or Haugr meaning gravesite in old Norse. This site later became 'College Green' after the Reformation and the establishment of Trinity College. It's said that in the late 1600s that Viking graves were still to be seen at Hoggen Green. He also sponsored the successful career of churchman St Lawrence O'Toole (Lorcán Ua Tuathail). He married O'Toole's half-sister Mor in 1153 and presided at the synod of Clane in 1161 when O'Toole was installed as archbishop of Dublin. Exile and return In 1166, Ireland's High King and Mac Murchada's main ally Muirchertach Ua Lochlainn had fallen, and a