Before Aug 1538 the Exeter Conspiracy was an attempt to overthrow Henry VIII (age 47) and replace him with Henry Courtenay 1st Marquess Exeter (age 42), grandson of Edward VI, Henry's first cousin. Thomas Audley 1st Baron Audley Walden (age 50) presided. John de Vere 15th Earl of Oxford (age 67) sat in judgement. Thomas Fiennes 9th Baron Dacre Gilsland (age 23) was juror.

In Aug 1538 Geoffrey Pole (age 37) was arrested. He had been corresponding with Cardinal Reginald Pole (age 38). The investigation of Henry Courtenay 1st Marquess Exeter (age 42) had turned up his name; he had appealed to Thomas Cromwell, who had him arrested and interrogated. Under interrogation, Geoffrey (age 37) said that his eldest brother Henry Pole 1st Baron Montagu (age 46), and Henry Courtenay 1st Marquess Exeter (age 42) had been party to his correspondence with Cardinal Reginald Pole (age 38).

In Nov 1538 Margaret Pole Countess Salsbury (age 65), her son Henry Pole 1st Baron Montagu (age 46), his son Henry Pole (age 18), and other Pole family members, and Henry Courtenay 1st Marquess Exeter (age 42), his wife Gertrude Blount Marchioness of Exeter (age 35), their son Edward Courtenay 1st Earl Devon (age 11) and Edward Neville (age 67) were arrested and imprisoned on charges of treason. Cromwell had previously written that they had "little offended save that he [Reginald Pole] is of their kin". They were committed to the Tower of London [Map].

Chronicle of Greyfriars. 09 Dec 1538. And this yere in December was beheddyd at the Towre-hyll lorde Henry markes of Exceter (age 42), lorde Henry Montegew (age 46), and sir Edward Nevelle (deceased).

In Jan 1539 Geoffrey Pole (age 38) was, somewhat surprisingly given the executions of the rest of his family, pardoned.

In Jan 1539 Cardinal Reginald Pole (age 38) was attainted in absentia.

Chronicle of Greyfriars. 03 Mar 1539. Also the 3rd day of March was beheaded at Tower-hill [Map] Sir Nicholas Carew (age 43).

Hall's Chronicle 1538. 03 Nov 1539. The third day of November were Henry Marquess of Exeter and Earl of Devonshire (age 43) and Sir Henry Pole knight and Lord Montague and Sir Edward Neville brother to the Lord Bergavenny sent to the Tower which three were accused by Sir Geoffrey Pole (age 38) brother to the Lord Montague (age 47), of high treason, and the two lords were arraigned the last day of December, at Westminster before the Lord Audley of Walden, Lord Chancellor, and then the High Steward of England, and there found guilty, likewise on the third day after was arraigned Sir Edward Neville, Sir Geoffrey Pole and two priests called Croftes and Collins, and one Holande a mariner and all attainted, and the ninth day of Januarie, were the said two lords and Sir Edward Neville beheaded at the Tower Hill, and the two priests and Holande were drawnn to Tyburn, and there hanged and quartered, and Sir Geoffrey Pole was pardoned.

In 1540 Gertrude Blount Marchioness of Exeter (age 37) was released.

On 03 Aug 1553 Edward Courtenay 1st Earl Devon (age 26) was finally released from imprisonment after fifteen years by Queen Mary I of England and Ireland (age 37) who was a close friend of his mother Gertrude Blount Marchioness of Exeter (age 50).