From Irish Roots, 1994 #2, "Surnames of County Tipperary" page 26:
There is a picture of the Butler tower at the castle of Nenagh. It says below the picture: Only the cylindrical tower or keep survives of the formidable castle at Nenagh built around 1220 by the Butlers, later Lords of Ormond. It is now almost 100 feet in height, the castellated ramparts having been added in 1860. The reason for this ornamental addition makes a rather puzzling story The bishop of Killaloe sent a curate to the USA to collect money for the construction of a new diocesan cathedral. However, the priest's mission was not very successful; he collected so little money, in fact, that the bishop had to abandon the idea of building a cathedral. The funds that had been collected were then used to rebuild the top of the Butler tower.

THEOBALD, 2nd Butler, who first assumed the name of LE BOTILER or Butler 1221; b. 1199/1200, served with the Earl of Pembroke 1223 and in the Gascon Campaign 1229; m. lstly, Joan, eldest sister and co-heir of Geoffrey de Marreis, Justiciar of Ireland ( to whose estates in that kingdom and in England, his posterity succeeded), by whom he had a son. He m. 2ndly, at the special request of the King, 1225, Rohesia, dau. and heiress of Nicholas de Verdon.

The cantred of Ormond, which the descendants of Fitzwalter, in the reign of Edward III preferred for the style of their Earldom to the more ancient one of Carrick, was their chief manor, in the centre of which Fitzwalter built for his residence and the seat of his jurisdiction the Castle of Nenagh; a pile that, to judge by its ruins, might have been almost royal. In front of a circular keep, unapproached in height and size by any similar remains in Ireland, stands the ruins of a great baronial hall; where, no doubt, were entertained on business or at festivals the freeholders, who did suit and service for their lands held of the manor, that district being at that time planted and settled by the tenants and followers of Fitzwalter, who held by knight's service as of the Castle of Nenagth. Around the castle grew up a town, inhabited by English artisans. In addition to the Round Tower, which is 100 feet high, and the remains of the baronial hall, there was an outward wall, whose total length was 600 yards, surrounding the castle yard after the Norman style. There were also four circular towers of smaller size connected by curtain walls and a lofty portcullised gate, which was approached by a high and well flanked causeway.48

After the death of the first Butler the possessions of the family were divided into two great manors; Weperons, perhaps Thurles and Nenagh; their possessions extended into County Limerick and included the baronies of Owney and Ara.48

The second Thoebald FitzWalter continued to hold the possessions of his father, and the office of Chief Butler. It was he who first formally assumed the title of Le Botiler or Chief Butler in the year 1221. This Butler lived at Nenagh without trouble from his enemies. The second Theobald was only 5 or 6 years old at the time of his father's death; at his coming of age in 1221 he was put into possession of the greater part of his estate in Ireland; but a third part of it continued nearly all his life in the hands of Fulk FitzWarine, who had married his mother in 1207. Fulk enjoyed this privilege by a writ of the king. Theobald received the possession of only part of his English estates for the same reason. Theobald, while still a minor married Joan, sister of John de Marisco, of an ancient Norman family, who was a considerable Baron in Ireland, and thus became heir to the property of de Marisco in Ireland and England. He gave a considerable part of his lands that lay near the church to the Priory of All Saints at Dublin.48

Weis' "Ancestral Roots. . ." (70:30), (149:28). Cokayne's "Complete Peerage" (Butler, p.448). In 1229 he was summoned to attend KING HENRY III into Brittany. He was Lord Justice of Ireland in 1247.