General Notes

He was of Rathregan Meath, Ireland. He was Deputy Governor of Ireland in1432. He came into the lands in the area through marriage with JoanCusack, whose father held Dunsany and Killeen. He was a knight at KilleenCastle.
DUNSANY AND DUNSANY'S CASTLES:
Dunsany Castle and Demesne are situated in the townland of Dusany ( DunSamhnaigh), between the historic town of Trim and the village ofDunshauglin in County Meath, Ireland. Meath ( the current county andWestmeath together) once formed a separate, fifth, province of Ireland,which was the territory of the High King (Ard Ri); today , this is allwithin the eastern province, Leinster. The former seat of the High Kings,Tara, is only a few kilometers away. Also nearby are the village ofKilessan the Bective Abby.
ORIGINS: The castle was established as a towered fortification of theNorman Pale ( an area of strong English control in the east of Ireland,established shortly after Strongbow's invasion) in the period 1180-1200;construction is believed to have begun in 1180-1181. The first  Normanbuilding on the site was a motte-type fortification on the mound betweenCastle and Abby, believed to have been the site of the Dun ( fortress)for which the area and demesne are named. Parts of the original buildingstill stand- the huge foundations and the four main towers  form a keypart of the current structure. Much additional work has , of course, beenperformed over the years, especially in the 18th and 19th Centuries, andcurrent Castle is more than three times the size of the original.
PLUNKETTS OF DUNSANY:
The Plunkett connection began with the knight Sir Christopher Plunkett (Deputy Governor of Ireland in 1432), who had come into the lands in thearea through marriage ( with Joan Cusack, whose father held Dunsany andKilleen), and two of his sons, John and  Christopher. John, the eldest ,was heir to nearby Killeen Castle ( his family were Lords of Killeen andlater became Earls of Fingall also), while Christopher was given Dunsany,becoming it's 1st Lord ( it is one of the oldest Irish titles, created bysummons in 1439 under Henry VI; documentary from later under Edward IV)Family legend relates  the the sizes of the demesnes of the two castleswas decided by race, with Killeen, starting from higher ground, havingthe advantage. In the same generation, the Church of St. Nicholas, withinthe demesne, was reputedly built after a rift between Lady Dunsany andLady Killeen- the two families had both used the church at Killeen- withthe specification that it be one foot bigger in length, breadth, andheight than Killeen Church.  The Castle is one of the oldest continuouslyinhabited buildings in Ireland, though the Lords of Dunsany have sufferedtribulations on a couple of occasions. The ninth Lord,elected by theCatholic peers of Ireland to asset their loyalty to the State, wasimprisoned for several years in Dublin Castle before being sent toConnaught; his family died on the  journey. He was reinstated at the timeof the Restoration. The tenth Lord fought for James II as the Battle ofthe Boyne an was outlawed but the estates were restored to his successorafter the Treaty of Limerick.
THE PLUNKETTS -- the line of the Plunkett nobility, so prominent in themid-and north-east, can be traced back to Johan(?) Plunket of Beaulieu (now Bewley) near Drogheda in County Louth. The Dunsany branch descendedfrom Richard Plunkett of  Rathregan in southern Meath, whose grandson,Christopher, married into the de Cusack family,. who held substantiallands including Killeen and Dunsany. Christopher was a  Knight and heldoffice as Sheriff of Meath and later, Deputy Governor of Ireland; he wascreated as first in the continuing line of Lords of Killeen ( hisfather-in-law had held this title by summons). His eldest son, John, wasto inherit Killeen, while the second son, another Christopher , was givenDunsany ( Killeen and Dunsany were twin castles of the  Norman Pale,dating back to the 1180's), becoming it's first Lord. Other sons tookholdings at Dunsoghly, Rathmore and Balrath. Information taken from website www.Dunsany.net/plunkett.htm on August 15,2002
Christopher Plunkett of Rathrergan, County Meath, and of Killeen, was sonand heir of Richard Plunkett of Rathrergan, by Elizabeth. He was a minorat his father's death, circa 1376, but in 1391, was sued  to take upknighthood, having the necessary territorial qualification in CountyMeath. He is not, however, styled a knight till about 1425. From 1401onward he is found acting as a Justice of the Peace, commissioner, inCounty Meath and was at one time sheriff of that county. In October 1402he was going to England, and  appointed attorneys. In 1403 he wasenfeoffed of the manor of Tillahuog ( Tullaghanoge, County Meath), tohimself and his male issue, with remainder to William and Richard, sonsof John Plunkett. He had pardons at various times. He was present at agreat Council at Naas between 1414 and 1419. On February 6,1426 he had agrand total of 20 marks on account of his great expenses in the wars inIreland. Though he is alleged by some to have become a peer at about thistime, he is never styled anything but a knight. He married, beforeOctober 1399, Joan, daughter and heir of Sir Luke De Cusake, with whom hehad the lordships and manor of Killeen, Kilskire, Killallon,Clonmacduffe, and Clony.
Per Burke's Irish Family Records 1976

Note: Knight; Deputy Governor of Ireland 1432; common ancestor of theBarons Dunsany and the Earls of Fingall. Served in Ireland under SirThomas Stanley and then under Richard, Duke of York. 1