High Quality Content by WIKIPEDIA articles! Thomas Percy (c. 1560 – 8 November 1605) was a member of the group of provincial English Catholics who planned the failed Gunpowder Plot of 1605. A tall, physically impressive man, little is known of his early life beyond his matriculation in 1579 to Peterhouse College in Cambridge, and his marriage in 1591 to Martha Wright. In 1596 a distant relation, Henry Percy, 9th Earl of Northumberland, appointed him constable of Alnwick Castle, responsible for the Percy family`s northern estates. He served the earl in the Low Countries in about 1600–1601, and in the years before 1603 was his intermediary in a series of confidential communications with King James VI of Scotland.