Duke of York and Mary Anne Clarke
Mary Ann Clarke attempted to blackmail her ex-lover, the Duke of York — who led the British army — by threatening to publish his letters. Sounds similar to Wellington but it takes a turn: His political enemies took notice, and they discovered that Mary Ann was selling army commissions (meaning, men who wanted a military rank or promotion would pay off Clarke, who would then demand that the Duke give her clients what they wanted). See omnystudio.com/listener for privacy information.