Conor na Siudane Ua Briain

Conor na Siudane Ua Briain (epithet deriving from the place of his slaying) also by the descriptives "Roe" (Conor Roe Ua Briain) and also as "broad-eyed" was a King of Thomond, in medieval Ireland. He was the son of Donnchadh Cairbreach Ó Briain.

During his reign English interference in Thomond became very marked. Tradraige was granted to Robert de Musegros, and the castles of Ogormack (Clare) and Traddery (Bunratty) were built in 1249-1253. Conor, however, by offer of yearly tribute, was confirmed in the rest of Thomond and the English were nearly completely expelled in 1257 by him and his son Tadhg.

In the year  1267,  accompanied  by  the  O'Deas,  the  O'Hehirs, and  other  tribes  of  Uí Cormaic  and  Cineal Fermaic,  Conor marched  into  Burren  to  enforce  the  submission  of  the  inhabitants, and  was  opposed  by  Conor  Carrach O'Loughlin,  who  had  been  informed  by  his  scouts  that  the prince  of  Thomond  had  but  a  comparatively  small  force. O'Loughlin, besides  his  own  followers,  was  assisted  by  the sons  of  Domnall  Connachtach  O'Brien,  uncle  to  Conor,  the reigning  prince,  who  had  settled  in  the  north-west  of  Thomond for  some  time  past. The armies  met  at  the  wood  of Siudan,  in  the  present  parish  of  Drumcreehy,  and  a  battle ensued,  in  which  Conor  lost  his  life. With him,  according to  the  annalists  of  the  Four  Masters,  who  record  the  event at  the  year  1268:.

"“The age of Christ, 1268. Conor Roe O’Brien, Lord of Thomond, Seoinin, (i.e. little John) his son, his daughter, his daughter’s son, i.e., the son of Rory O’Grady, Duvloughlin O’Loughlin, Thomas O’Beollan, and a number of others, were slain by Dermot, the son of Murtough O’Brien, for which he himself was afterwards killed; and Brian, the son of Conor O’Brien, then assumed the lordship of Thomond.” "

The Cistercian monks buried him in the nearby Corcomroe Abbey and a stone effigy was built of him which is still well preserved. It was probably made by the same artisan who made the effigy of King Felim O'Connor (died 1265) in the Priory of St. Mary in Roscommon as the monuments are generally identical in their clothing and details, although this second royal effigy is in a much worst state of degradation with the face being entirely obliterated.

On his death in 1268 he was succeeded by his son Brian Ruadh Ó Briain. His eldest son Tadhg Cael Uisce had pre-deceased him in 1259. A feud which was fostered by the Norman de Clares emerged between the descendants of Tadhg (Clann Tadhg) and Brian (Clann Briain) over the kingship of Thomond and lasted until the 14th century with the senior Clann Tadhg eventually being victorious.

Family and issue
He married Mór, daughter of McNamara, Lord of Uí Coileann (Clann Cullin) and had issue:
 * Tadhg Cael Uisce Ó Briain
 * Brian Ruadh Ó Briain
 * Seonín (Little John) Ó Briain
 * Murtogh Ó Briain