When Henry IV seized the throne from his cousin Richard II, people saw it as a hopeful new beginning for England. The first monarch to have English as his mother tongue since the Norman conquest, Henry seemed to embody the ideals of chivalric kingship: mercy, piety, military prowess and learning. Yet deposing a crowned monarch was not a stable foundation on which to build a reign. Henry IV found himself challenged from all sides, plagued by conspiracies, rebellions, assassination attempts and crippling debts, while his tense relationships with Parliament and with his own son, Shakespeare's Prince Hal, saw his grip on power falter. Nevertheless, he was the first king and founder of a Lancastrian dynasty which would go on to shape England for centuries to come. In this lively study, Catherine Nall reappraises a monarch who weathered upheaval and uncertainty and held on to the throne through sheer force of will.