Career
He was an assistant to Edward Courtenay, the first earl of Devon. Devon was suspected of involvement in Wyatt"s rebellion against Mary, and Tremayne was taken to the Tower of London in 1554. There he was tortured on the rack for evidence but kept silent.
After ten or eleven months in prison, he was released on a £40 fine, and he left England for Italy with Courtenay.
He wanted to join Sir Henry Sutton Dudley"s conspiracy against Mary, and he joined the camp of English rebels at Rouen before the conspiracy was exploded in April 1557. He then attached himself to Francis Russell, 2nd Earl of Bedford, who was another figure plotting against Mary.
When Elizabeth assumed the throne, she rewarded Tremayne. From 1561-1574, he was the chief recipient of royal taxes for the district.
He was also interested in the conversion of Ireland.
William Cecil had asked him to study the question, and he wrote Causes why Ireland is not Reformed. In 1571, he was a clerk of the Privy Council.