Henry IV (1367-1413), son of John of Gaunt, Duke of Lancaster, was the first king of the House of Lancaster. He was often called Henry of Bolingbroke. He defeated his cousin, King Richard II, in 1399, and parliament elected him king. Henry admitted that parliament had the right to choose the king. This admission formed an important increase in parliamentary power.
Revolts and conspiracies marred Henry's reign, but he put them down with great effort. He encouraged towns to develop, and helped England's growing trade. However, he was intolerant of religious differences, and persecuted the Lollards.