The Southampton Plot

The Scheme that nearly dethroned England’s Infamous Warrior King

May 02, 2024

Southampton, in the the very south of England is today mostly know for its very busy port (which I can testify travelling out of there on Monday) as well as it’s football club, currently in the Second Division of English Football. However behind its thick salty air, it’s towering Football stadium and the day - to - day activity of its busy port, lies a hidden history, a hidden plot. A plot to a kill a king. Not just any king but one of Englands greatest warrior kings, Henry V.

The plot that looked to kill Henry as well as his brothers would have brung the Lancastrian Dynasty crashing down only as it had started to rise.

Though the plot to murder the king had a substantial as well as influential backing including the kings own cousin and friend, Richard of Conisbrough, Earl of Cambridge as well as trusted members of his inner circle it was ultimately foiled before a dagger could be raised by the very man the rebels had looked to make king. Henry whose dynasty had already dealt with its fair share of existential threats cracked down on the plot hard, seeing his own cousin beheaded alongside the rest of the plotters.

Out of the port and into the seas, Henry’s fleet would land upon the sands of France and would go onto fight a battle that would go down in English history.

In truth, a plot or insurrection against a king in this period was nothing new especially for the recently established House of Lancaster. The king’s father and predecessor Henry IV had famously usurped a he throne from his feckless cousin Richard II. Richard was the son of the eldest of the warrior king Edward III’s many sons. Edward, The Black Prince as he became known had almost been as brilliant as his father, fighting in some of the major battles of the first phase of the Hundred Years’ War. He had however died in 1376 likely as a result of the painful disease, dysentery. His death was soon followed by that of his revered father Edward III only a year later

Richard II who came to the throne at only 10 years old had what can only be described as a disastrous reign. A reign in which peasants had stormed the capital, taking over its HQ, The Tower, favourites prospered from the king’s generosity and his powerful nobles locked to crack down on his authority. Those that opposed Richard would be met with a tyrannical response of imprisonment, exile, execution and murder. It would be the treatment of his cousin Henry Bolingbroke however that would prove to be his downfall.

Bolingbroke’s Father John of Gaunt, Duke was the wealthiest nobleman in the realm and the third son of Edward III. Upon his death in 1399 all his lands, titles and wealth should have passed down to his recently exiled son however as Richard’s tyranny peaked he kept hold of the wealth and lands for himself increasing his already substantial revenues. The king would pay the price with his crown.

Henry returned back to England under the guise of receiving his rightful inheritance, the Duchy of Lancaster, he hid his ulterior motive well. Whilst the king was in Ireland, Henry garnered large amounts of support in England, another to overthrow Richard and have himself crowned king.

Richard’s death a few months later likely as a result of starvation looked to seal Henry’s grip on the throne and establish his he House of Lancaster as England’s ruling dynasty.

Henry IV’s reign would prove to be dogged by insurrection and rebellion. He faced conflict against England’s ancient enemy Scotland, a revolt in Wales led by the rebel/hero Owain Glyndwr who would give the king a headache for well over a decade and finally Henry would find rebellion in his own kingdom, led by the real kings in the north, the notorious Percy family led by the battle - hardened Henry ‘Hotspur’. Henry would also face a claimant threat to his hard - won throne, that of Edmund, 5th Earl of March, the same that would prove a dynastic challenger to Henry V only 15 years later. Henry faced problems on all sides however they were successfully dealt with. The House of Lancaster looked to remain safely seated on the throne, for now….

Though by Henry IV’s death in 1413 the situation had simmered this is largely the kingdom that Henry V would find himself. His initiative however was not to quash rebellion at home but to look across the English Channel to the land of his ancestors, the land of his enemies, the land of the king’s of France. This is the very reason we find Henry and his large retinue in the bustling city of Southampton during the scorching summer of 1415.

Edmund Mortimer, 5th Earl of March had proved to be a tricky problem for the recently established House of Lancaster. The major problem was simply that he posed a better claim to the throne than the current dynasty ruling England. Edmund’s two times great - grandfather was Lionel of Antwerp, Duke of Clarence, who was importantly the second son of Edward III. As a result, the Mortimer family had largely been touted as the successors to the childless Richard II before he was disposed by Henry IV

The claim had proved to be a thorn in the side of England’s first Lancastrian king and dug further into the side of it’s second.

Though March proved to be central to the plot he was also pivotal in bringing it crashing down.

The main ringleaders were the king’s cousin Richard of Conisburgh, Earl of Cambridge, Henry Scrope, 3rd Baron Scrope of Masham and Sir Thomas Grey of Castle Heaton. The involvement of Cambridge is particularly surprising. A member of the king’s own family (his father being the fourth of Edward III’s son Edmund of Langley, 1st Duke of of York), Cambridge had profited much from his cousin’s reign. The Earl however had ties to the man the rebels would make king being his brother - in - law from his first marriage. His second was to the erstwhile enemies of his he House of Lancaster, the Percy’s.

Talks were taking place in Southampton which was becoming a hub of activity as England readied itself to invade and conquer France. Though Scrope had proved to be a loyal advisor to the king he partook in the plot and looked to overthrow him. Communication lines were set up across the country as the plan was being put into action with the result being the deaths of Henry V, his brothers Edward the Dukes of Bedford, Clarence and Gloucester leaving Edmund Mortimer to claim his birthright and sitting upon the English throne. There was only one more piece of the puzzle, having to tell the Earl of March that he would be king.

Though the plot was built around March it seems that he was completely oblivious to it. Since his insurrection under the reign of Henry IV he had redeemed himself to the Lancastrian cause and was even in Southampton reddening himself and his men for the invasion ahead. When the news reached his ear, it proved to have an undesired affect. On 31st July, Edmund went to the king his supporters looked to have murdered and exposed the plot in full.

Henry did not wish to mould his reign into what his father’s had become, ruling over a land of intrigue, backstabbing and revolt, Henry cracked down on the rebellion hard. As English ships creaked in the waters of Southampton the plotters were arrested, and a trial took place. The king’s intense gaze and the smoking gun that was the Earl of March sealed the three men’s fate. Grey was the first to be executed, taking place on the 3rd of August shortly followed by Cambridge and Scrope. The king present for both.

A plot that could have rocked England to it’s core had been smothered in a matter of weeks. Feeling that his own lands were secure for now, Henry V and his armies sailed for France reigniting the Hundred Years’ War and a inflicting a devastating defeat on the French at the Battle of Agincourt, a battle that would go down in history.

The Southampton Plot was not the first nor the last insurrection the House of Lancaster. It would be the Earl of Cambridge’s own son by his first marriage, Richard of York, 3rd Duke of York that would ultimately challenge Henry VI for the throne, igniting a 30 year long civil war.

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