There are two hundred years between these two notable monarchs, and we will look at the English one first. Both are important in history, over-balanced by ambition, bothered by religion, and chased by bad luck.
Henry of Bolingbroke, I Duke of Hereford, II Duke of Lancaster was born the only legitimate son of John of Gaunt (q.v.) in 1366. Gaunt, I Duke of Lancaster, was the second son of Edward III. His elder brother was known as the Black Prince, who died before he could become king.
Bolingbroke was roughly thirty years old when King Richard II (grandson of Edward III) banished him from the realm for reasons best known to this slightly deranged young man. If Bolingbroke had not been banished, he would have inherited the really vast estates left by his father at his death in 1399. Gaunt owned almost as many castles and manor houses in England as Gilles de Retz (or Rais) had in France (q.v.). Among these was a mansion called The Savoy, by the River Thames.
Bolingbroke, exiled by his king, and backed by other barons, decided to retaliate by invading England at the head of a not inconsiderable army. Certainly it was large and efficient enough for Henry to defeat Richard in battle and take his throne as a usurper. He was not the first aristocrat nor would he be the last to usurp the throne of England.
Henry IV, as he was named at his coronation, found his position as king difficult to defend or hold. He needed the support of the Church, which he obtained by persecuting the Lollards (q.v.). As this was the fourteenth century he also desperately needed military and moral support from other nobles, and that was a difficult task, because so many of them wanted to be king too. There was a House of Commons, working more or less well, though kings were absolute then, and Henry needed the support of Members, especially in terms of money. Ominous threats were coming from Wales in the form of a Welsh noble and semi-wizard called Owen Glendower. Threats from the North, virtually owned and governed by the Percys of Alnwick, were real too. To cap it all, the once fit and clever soldier fell ill, and stayed ill during the sad last years of his life, but he was not so ill that he couldn’t produce a son who would in time become one of the greatest of English monarchs – Henry V.
Henry died when he was only 47 years old; Henry V (‘Prince Hal’ in Shakespeare) defeated the French at Agincourt, married a French princess, and died at 35.
Henry IV, King of Navarre was born in Pau in 1553, and became the first Bourbon King of France. Strangely for that time he was brought up a Calvinist by his anti-Catholic mother, Queen Jeanne d’Albret of Navarre.
Not surprisingly, he became a Huguenot (French protestant), and in 1572 married Marguerite de Valois; he was nineteen. Hardly had the brief honeymoon finished when Henry narrowly avoided death during the Bartholomew’s Day Massacre, a matter of religion if ever there was one. In fact Henry escaped with his life by professing to his assailants that he was a Catholic.
Kept prisoner by the Catholics until 1576, he was able to escape and take up his religion again as a Protestant. Later he played a prominent part in The War of the Three Henrys (four years of it), ending up as King of France in 1589. This was when he is alleged to have said, “Paris is worth a Mass”. His reign brought peace at last to France, partly by establishing certain political rights and a degree of religious freedom for the Huguenots (the Edict of Nantes q.v.). Not fond of Hapsburgs, he maintained a fervently anti-Hapsburg policy. He is considered by some historians to be the founder of the absolute, centralized monarchical regime which was to dominate seventeenth and eighteenth century France.
He might have twice claimed himself to be Catholic during his life, and made that remark about Paris being worth a Mass, but this did not save him from a Catholic assassin’s knife in 1610. One of the oddest coincidences in history is that the hunting knife used on Henry of Navarre had already been used in an attempt on another king’s life – this time in Scotland (q.v.). James VI of Scotland and I of England was nearly murdered by the Ruthvens in a Scottish castle (q.v.).: it was later proved that the same deadly weapon was used in both incidents, though James I survived, while Henry of Navarre did not.