How Historically Accurate Is The King
The recent Netflix move The King takes place in the early 14th century during the reign of Henry IV's last years and rise of Henry V. The movie shows Henry V as an unlikely king, who was more accustomed to being drunk and being with women, but he rapidly matures and eventually takes his place as king and lead England to a major victory against France in the 100 Year War.
Near the end of Henry IV's reign, around 1413, the English kingdom is beset with rebellions in Wales and troubles with the Scots. Henry, called Hal, is away from the king, where the relationship between father and son are tense. The king is sick but he increasingly sees his younger son, Thomas, as the likely successor to the throne. Henry Percy, and the Percy family, is initially an important noble family supporting the king.
However, they soon rebel and join the Welsh against the king. The king sends his son, Thomas, to deal with Percy, but Henry, having learned his father would not choose him as successor, went to support his brother in Wales. Henry provoked Percy into single combat and eventually Henry was successful and killed Percy. His brother was not satisfied by this and decided to pursue the battle against the Welsh anyway. However, he was killed in the process. This then made Henry the likely successor and Henry IV realized this as he lay dying.
Henry V is now king and he determines to rule in a way that is different from his father, choosing to unit England and its various key households and lands. During the feast to honor the new king, the Dauphin of France sends an insulting gift of a child's ball, which is interpreted to be an insult regarding the age and maturity of the king. Soon after, an assassin is found who is supposedly sent by Charles VI, the King of France. This is interpreted as a threat to the king and Henry decides to embark on war against France, effectively resuming the One Hundred Year War.
The Chief Justice, William Gascoigne, strongly encourages war and two nobles, The Earl of Cambridge and Thomas Grey, having conspired against the king are executed. Henry soon sets sail to France with his army. They are quickly successful in taking a fortress town Harfleur in the Normandy coast. The Dauphin of France, meanwhile, seeks revenge and begins to assemble his army against the English king and his invading forces.
The English army, as it advances, notices now that the French army assembled against them is much larger. The night before battle, Falstaff, a trusted friend to the king, advises to feign a small attack, drawing the French army in towards them, and then surrounding them as the rest of the English army hides in nearby woods and then they could also hit them hard with their longbows. The next day, the king offers to fight the Dauphin in single combat to end hostilities; he refuses and the battle commences. The plan devised works well and the English resoundingly defeat the French at the Battle of Agincourt, although Falstaff is killed.
The Dauphin does offer to fight the English king, but is easily defeated and captured. Now the path is clear to Paris, but at this point Charles VI effectively surrenders and offers his daughter Catherine to the king. This ends hostilities but Henry eventually learns from his new wife that Gascoigne had manipulated the king into launching the war against France, as no conspirators were actually sent by the French king. Henry then kills Gascoigne. The king is then celebrated by his people as he takes the hand of his wife, celebrating the fact he has now united his kingdom and is victorious.
Henry IV: He is the initial king shown in his last days. His kingdom is beset with strife and he seems unable to placate his country. A lot of this has to do with how he came to power, having effectively deposed Richard II and many rebellions resulted because of the issue of succession to the English throne and rebellions and war by Scotland and Wales.
Thomas: The younger son of Henry IV is shown as a would-be king trying to please his father and also jealous of his older brother Hal (or Henry V). He dies in battle, showing poor judgment in launching a battle that did not need to be fought.
Henry V: He is depicted is initially being immature and not wanting to be king. However, initially he wants to support his brother and after his brother's death he sees it is his responsibility in correcting the mistakes of his father by uniting the kingdom. He does not want war with France, but feels he must act after believing French agents attempted to kill him.
William Gascoigne: Initially, he was shown as a trusted adviser who could help the young king navigate politics in the early 14th century. However, he was later depicted as someone more interested in manipulating the king to launch a war that was not needed simply to advance his own interests.
John Falstaff: A fictional character created by Shakespeare in his book Henry V, which the movie is in part based on. He is depicted as a drinking friend to the king who was also an old warrior. He comes up with the idea to trap the French in the Battle of Agincourt, but is killed in the battle despite English success.
Catherine of Valois: The French consort of Henry V, she is depicted as an intelligent woman who forces the king to think about his actions and determine the roots of why given actions occurred during the war against France. She helps the king realise he was being manipulated by Gascoigne. 
The movie is largely based on Henry V and Part 1 and 2 of Henry IV by Shakespeare, which means that it takes a lot of liberties in how it interpreted historical events. In fact, many characters and events, while historical, did not occur or result in how they are portrayed. For one, Thomas was never heir to the throne, as far as we know, and he died long after Henry IV died. He also died fighting the Scots at the Battle of Baugé in France. Henry Percy is killed in a rebellion against Henry IV, but at the Battle of Shrewsbury rather than in combat with Henry V, although it is unsure who killed him. Henry V was also very much interested in war with France early on, although he may have seen this as a way to unite his own kingdom.
Falstaff is a made-up character and Henry V, rather than being somewhat irresponsible in his youth, was actually very active in his father's affairs from an early age. Already during the reign of his father, Henry was leading many of the battles against rebellions that occurred and thus was an experienced warrior before he became king. Henry V did fall out for a while with his father, but soon much of the kingdom rallied around Henry V after his father died. Additionally, William Gascoigne resigned soon after Henry V became king. He, in fact, had little influence on the king and events surrounding the war in France.
The depiction of key events such as the Battle of Harfleur and Battle of Agincourt are accurate, as well as some of the events as to how the English gained these key victories. Mainly, the English longbow played a decisive role in the French campaigns, as the French did not have an effective counter to this. The English were able to kill many leading French nobles, creating a crisis in France that led to the French king offering his daughter to the English king. The Dauphin also was never present in the Battle of Agincourt. In fact, he died soon after from dysentery. In fact, the death of the Dauphin and Henry's success led to the French king wanting to make Henry the future king of France. This never happened because Henry V died from his own infection of dysentery and the crowns of England and France proved they could not be united so easily as the French reneged the treaty signed earlier that would have united the two kingdoms.
Overall, The King does appear a lot like the plays by Shakespeare, which were effective propaganda for Henry V. Eventually, Catherine remarries a man called Owen Tutor, who gives rise to the Tutor dynasty that influenced Shakespeare and his writing. The events concentrate on the events leading to the Battle of Agincourt, which showed the king as a mature war leader. However, in reality, Henry V was groomed as heir apparent and as a war leader early on in his life and he was already successful militarily before he became king.
The film The King largely follows the works by Shakespeare, which in many ways skews its historical accuracy. Henry V was a celebrated king for his decisive leadership and actions, particularly at Agincourt, but in reality, he was also very ambitious and he showed great promise as king even in his younger years. The movie does depict many key events but takes liberty with characters in depicting them. For instance, there is no indication William Gascoigne betrayed the king or manipulated him into war.
- For more on Henry IV and the troubles surrounding his reign, see: Dodd G and Biggs D (eds) (2003) Henry IV: The Establishment of the Regime, 1399-1406. Woodbridge, Suffolk ; Rochester, NY: York Medieval Press in association with Boydell Press.
- For more on Thomas, see: Allmand CT (1997) Henry V. New ed. Yale English monarchs. New Haven, Conn. London: Yale Univ. Press.
- See also: Allmand CT (1997) Henry V. New ed. Yale English monarchs. New Haven, Conn. London: Yale Univ. Press.
- For more on the historical Gascoigne, see: Paxman J (2007) The English: A Portrait of a People. London: Penguin Books, pg. 361-3.
- For more on Falstaff, see: Shakespeare W (2009) The History of Henry IV, Part 1&2.
- For more on Catherine, see: Rockefeller LA (2014) Catherine de Valois: French Princess, Tudor Matriarch.
- See: Allmand (1997) for further detail on key events during Henry V's reign
- See Allmand (1997) for further details