This period drama frames the tumultuous affair between Queen Elizabeth I and the man who would be King of England, Robert Devereux, the Earl of Essex. Ever the victor on the battlefield, Devereux returns to London after defeating Spanish forces at Cadiz. Middle-aged Elizabeth, so attracted to the younger Devereux but fearful of his influence and popularity, sends him on a new mission: a doomed campaign to Ireland. When he and his troops return in defeat, Devereux demands to share the throne with the heir-less queen, and Elizabeth, at first, intends to marry. Ultimately sensing the marriage would prove disastrous for England, Elizabeth sets in motion a merciless plan to protect her people and preserve her throne.