Henry IV was proclaimed king of England after a swift political maneuver that dethroned King Richard II in 1399. Initially, Henry Bolingbroke, a nobleman and Duke of Lancaster, had been in exile due to political strife with Richard II. He returned to England and gathered support against the king, capitalizing on discontent with Richard's rule. After successfully leading a rebellion and obtaining the support of significant nobles and the English populace, he executed a series of strategic moves that led to Richard's abdication. Henry's proclamation as king took place in London, where he was recognized as the sovereign ruler of England.

Richard II's deposition marked a pivotal moment in English history, as it ended the direct lineage of the Plantagenet dynasty that had ruled for centuries. The political landscape shifted dramatically as Henry IV ascended to the throne, bringing forth new challenges and opportunities for England. His reign was characterized by the need to consolidate power and stabilize the kingdom, which had been threatened by internal strife and the ongoing tensions of the Welsh and Scottish borders. Henry IV's rule began the Lancastrian dynasty, which would play a significant role in the Wars of the Roses.

The events surrounding Henry IV's proclamation were steeped in tension and uncertainty, shaping the future of England's monarchy. His claims to the throne were based not only on royal blood but also on the support of the English nobility and a desire to restore stability after the turbulent reign of Richard II. This rebellion and subsequent coronation would lay the groundwork for future conflicts that would arise within the monarchy, ultimately leading to battles over legitimacy and power.