I have just finished reading Dr. Ian Mortimer's book, the Fears of Henry IV.
Poor Henry, the first Lancastrian, is rather forgotten outside of Shakespeare. He was an important monarch, who overthrew the dictatorial Richard II, effectively ending the House of Plantagenet (though he might well have described himself as one). He was embroiled in a lengthy war in Wales, and was beset by plots against him. He had a famously terrible relationship with his wayward son Henry of Monmouth (later Henry V), who was probably more of an embarrassment than his famously philandering father, John of Gaunt.
The book is well written and a fascinating account of the whole life of Henry, as a popular and well rounded child, compared to his lonely and isolated cousin Richard. He was a great jouster and a celebrity knight, who was feted during his crusades. The book has interesting facts, such as Henry was probably the last King of England after the Norman Conquest who's first language was French.
I have some fascination for Henry IV, as I was a student at the University of Kent. I was fond, during my studies at Canterbury, of visiting the cathedral. Most famous for the murder and subsequent shrine of Thomas a Becket, the Tomb of Henry is a great jewel. Beautifully carved from alabaster, it is the nearest you can get to a King of England. He is buried in a place of honour, next to the former shrine of Becket. Opposite lies Edward, the Black Prince. Eldest son of Edward III, he is Henry's uncle, and awkwardly the father of Richard II, the man Henry overthrew.
Dr Mortimer also has an excellent book on Edward III, the Greatest King. I recommend that too. I do not subscribe to Dr Mortimer's views on the survival of Edward II, but barring that it is a good book.
I will not link to the amazon site, as I prefer to see books bought at bookstores or borrowed from a library. We should not let bookstores go the way of HMV by this destructive internet purchasing. And don't get it on a kindle either please.