Henry’s fifth queen is best known to history as the stupid adolescent who got herself fatally entangled with lovers and ended up on the block. However, there was more to her than that. She was a symptom of the power struggle that was going on in the court in 1539–40 between Thomas Cromwell and his conservative rivals, among whom the Howard family figured prominently. The Howards were an ambitious clan, and Catherine’s marriage to Henry appeared to signify their triumph. However, her weakness ruined them in the short term and permanently undermined the power of Thomas Howard, the 3rd Duke of Norfolk. Catherine’s advent has to be seen against the background of the failed Cleves marriage and the policy which that represented. Her downfall should similarly be seen in terms of the reformers fighting back against the Howards, and the fact that she brought down Jane Rochford with her. Politics and sexuality were inextricably mixed, especially when the king’s potency was called into question. It is time to have another look at her brief but important reign.