Elizabeth was the daughter of Henry VIII and Anne Boleyn and, despite being declared illegitimate following the annulment of her parents’ marriage, came to the throne as the next in line behind her Catholic half-sister under the terms of the Third Act of Succession.

The Pope granted the Latin title Fidei defensor to Henry after he published a book in which he defended Catholic doctrine against the criticisms levelled at it by Martin Luther in his Ninety-five Theses during the early stages of the Protestant Reformation.