On this day in 1571 Thomas Howard, 4th Duke of Norfolk, was arrested for his role in the Ridolfi plot to assassinate Queen Elizabeth I of England and replace her with Mary, Queen of Scots.
Roberto Ridolfi, a Florentine banker and ardent Catholic, had been involved in the planning of the Northern rebellion, and had been plotting to overthrow Elizabeth as early as 1569.
Mary’s advisor, John Lesley, the Bishop of Ross, gave his assent to the plot as the way to free Mary. The plan was to have the Duke of Alba invade from the Netherlands with 10,000 men, foment a rebellion of the northern English nobility, murder Elizabeth, and marry Mary to Thomas Howard, 4th Duke of Norfolk.
Ridolfi optimistically estimated half of all English peers were Catholic, and could muster in excess of 39,000 men. Norfolk gave verbal assurances to Ridolfi that he was Catholic, though as a pupil of John Foxe, he remained a Protestant all his life.
Both Mary and Norfolk, desperate to remedy their respective situations, agreed to the plot. With their blessing, Ridolfi set off to the Continent to gain Alba, Pius V and King Philip II’s support.