Due to the abdication of Richard II, Henry Bolingbroke was proclaimed King Henry IV of England on this date in 1399. Henry and other lords opposed the rule of Richard, who banished Henry in 1398 and seized his family's estates early in 1399. But Henry invaded England in July in defense of the rights of the nobility and Richard peacefully surrendered in August. Henry IV was the first monarch of the House of Lancaster. See http://www.history.com/this-day-in-history.do?action=Article&id=5385 for more information.