[1] He was the eldest son of William Caulfeild, 2nd Baron Caulfeild, and Mary, daughter of Sir John King, knight (ancestor to the Earl of Kingston) and his wife Catherine Drury.
In 1637 he entered Christ's College, Cambridge in April (aged 16), and Lincoln's Inn in October.
[3] In 1639 Caulfeild was returned to parliament for County Tyrone; in the same year, he succeeded his father as 3rd Baron.
[3] During the Irish Rebellion of 1641 he was given his father's old post as governor of Charlemont Fort which was of strategic importance as one of a handful of modern fortresses in Ireland.
[4] After being kept fifteen weeks a prisoner in Charlemont, Caulfeild was moved to O'Neill's castle at Kinard; and on entering the castle was shot dead by Edmund Boy O'Hugh, foster-brother to O'Neill, 6 January 1642.