The Accursed King:

What happens when a king loses his prowess? The day Henry IV could finally declare he had vanquished his enemies, he threw it all away with an infamous deed. No English king had executed an archbishop before. And divine judgment was quick to follow. Many thought he was struck with leprosy—God's greatest punishment for sinners. From that point on, Henry's health was cursed and he fought doggedly on as his body continued to betray him—reducing this once great warrior to an invalid. Fortunately for England, his heir was ready and eager to take over. But Henry wasn't willing to relinquish what he had worked so hard to preserve. No one was going to take away his royal prerogative—not even Prince Hal. But Henry didn't count on Hal's dauntless nature, which threatened to tear the royal family apart.

The Usurper King:

From Outlaw to Usurper, Henry Bolingbroke fought one rebellion after another.

First, he led his own uprising. Then he captured a forsaken king. Henry had no intention of taking the crown for himself; it was given to him by popular acclaim. Alas, it didn't take long to realize that that having the kingship was much less rewarding than striving for it. Only three months after his coronation, Henry IV had to face a rebellion led by Richard's disgruntled favorites. Repressive measures led to more discontent. His own supporters turned against him, demanding more than he could give. The haughty Percies precipitated the Battle of Shrewsbury which nearly cost him the throne—and his life.

To make matters worse, even after Richard II's funeral, the deposed monarch was rumored to be in Scotland, planning his return. The king just wouldn't stay down and malcontents wanted him back.