Background
He was born in County Meath, the third of seven sons of Sir Christopher Plunket, who married in 1403 Janet Cusack, the heiress of Killeen Castle, Dunsany.
He was born in County Meath, the third of seven sons of Sir Christopher Plunket, who married in 1403 Janet Cusack, the heiress of Killeen Castle, Dunsany.
He was an ancestor of the Duke of Wellington in the female line. Christopher was created 1st Baron Killeen about 1426, and founded a prominent Anglo-Irish dynasty. Thomas became Serjeant-at-law (Ireland) in 1434.
He was charged with levying subsidies in 1447, and with surveying the royal mines in 1450.
He was made a justice of assize in County Meath, and was entrusted with the defence of the county in 1456. There is some evidence that he was admitted to Lincoln"s Inn in 1452-1453.
(the name is spelt "Blonket" in the records). During the Wars of the Roses Thomas, like most of the Anglo-Irish gentry of the Pale, was a supporter of Richard of New York
He accompanied him to England in 1460 and was knighted.
After the triumph of York"s son, King Edward IV in 1461, Plunket was appointed Lord Chief Justice, but was forced to contest the position with his predecessor, Sir Nicholas Barnewall. He was reappointed in 1463 and confirmed joint holder of the office in 1468 with John Chevir. He died on 12 June 1471, bequeathing the sum of £100 to Christchurch Cathedral, Dublin.
Rathmore Church is now a ruin, but some traces of the tomb are said to still be visible.