In 1324, he presided at the trial of Alice Kyteler, the celebrated Witch of Kilkenny and her associates, and condemned several of them to death by burning.
[3] An ambitious programme to reform the Irish administration produced little result, possibly because it was delegated to his Deputy, John Morice, a long-serving and conscientious but not very competent civil servant.
[4] In 1342, he joined the Earl of Northampton on an expedition to Flanders and on his return was made Constable of Nottingham Castle (1343–1344) and of the Tower of London (1345–1346).
He took part in a number of wars against the Scots and French and fought at the Battle of Crecy in 1346, being sent home by the king to announce the victory in Parliament.
Darcy and Joan de Burgh had a daughter, Elizabeth, who married James Butler, 2nd Earl of Ormonde.