FTP, name this father of Henry IV, whose nickname is taken from the Belgian city of his birth.
This man was such a bad commander that his brother had to assume command from his deathbed to rescue the army from this man's incompetence.  After the death of his brother and father, he became regent to the young Richard II, and retained influence within the court until his death in 1399, despite his unpopularity, and his association with John Wycliffe.  FTP, name this father of Henry IV, whose nickname is taken from the Belgian city of his birth.
This man was such a bad commander that his brother had to assume command from his deathbed to rescue the army from this man's incompetence.  
John of Gaunt (Prompt on Duke of Lancaster)