Hales lost royal favour, however, by writing a succession tract entitled "A Declaration of the Succession of the Crowne Imperiall of Inglande", supporting the title to the crown of the descendants of King Henry VIII's younger sister Mary. Mary's granddaughter Lady Catherine Grey had secretly married Edward Seymour, and the Queen had had them both imprisoned. Hales took the position that if the Queen were to have no children, Lady Catherine should be next in line to the throne. Hales was imprisoned for his temerity. On 27 April 1564 Sir William Cecil wrote to Sir Thomas Smith that: