In late 1538, Cromwell moved against his former allies. Carew was already out of favour at court, having responded angrily to an insult made by King Henry VIII. Ambassador Chapuys perceived that the real cause of his downfall was likely the championing of the Princess Mary. When Cromwell presented apparently-treasonous letters written by Carew, King Henry VIII was persuaded that Carew had been involved in the Exeter Conspiracy, a plot to depose him and place Cardinal Reginald Pole on the throne in his stead. Carew was thus arrested and stood trial on 14 February 1539, and he was found guilty of high treason.