Only last year was the 500th anniversary of the Battle of Agincourt where the English troops defeated the French, and firmly made Henry V go down in history as the warrior king, the type of king the men around his son, Henry VI would later want him to be.
But often overlooked when discussing the battle is the incident that maybe could have put a halt to the triumphant expedition; the Southampton Plot.
There are historians who argue that the case may be that there never was a lot at all, only political moaning from noblemen not quite content with their lot in life, but whatever the case may have been, it didn´t matter much to the King once he was informed of what was said to be going on.
The three men behind the alleged plot were Richard of Conisburgh, 3rd Earl of Cambridge, Henry Scrope, 3rd Baron Scrope of Masham and Sir Thomas Grey
Richard of Conisburgh was a grandson of Edward III through his fourth surviving son Edmund of Langley and his wife Isabella of Castile, but his immediate descendants would come to be even more interesting for the upcoming decades in England; in 1415 he had left behind a four-year-old son, he too called Richard, who would grow up to become the Duke of York and father among other children the three boys Edward (IV), George and Richard (III). Not least was he a cousin of the King.
When his father passed he left nothing for Richard, nor did his brother and this has by some historians been taken as a sign that he was in fact not the son of Edmund, but of John St. Holland 1st Duke of Exeter, who allegedly had had an affair with Richard´s mother Isabella. She how ever had made requested that Richard´s godfather, King Richard II, granted her younger son an annuity of 500 marks, a request that was granted. The sum was further increased over the years.
But when Richard II was deposed in 1399, his successor Henry IV was less inclined to pay the annuity, and Richard would receive it either irregularly or not at all. As Richard of Conisburgh owned no lands, this was his only source of income.
The only significant appointments Richard of Conisburgh received in the years leading up to those days in Southampton was as commander over a force defending Hertfordshire against Welsh rebels and to escort princess Philippa to her wedding to king Eric of Denmark in 1406, prior to which he was knighted, so it isn´t hard to imagine that even though Henry IV died in 1413, there was some resentment brewing which may have been the reason for the assumed plot.
During his stay in Demark, he is believed to have become acquainted with Lord Scrope, who would later (in 1411) marry Joan Holland who for a few years after the death of Isabella of Castile had been married to Edmund of Langley.
Henry Scrope had at least seemingly a much better relationship to Henry V, in fact, he was considered to be a royal favorite who had been knighted in 1403 and fought alongside Henry IV at the battle of Shrewsbury that same year. Between 1406 and 1413 he had a number of diplomatic missions, and in 1410 he had been appointed Treasurer of England as well as Knight of the Order of the Garter. It is hard to see why he would get involved in plot at all, and historian Anne Curry suggests that he was simply fed up with Henry V and his French campaign.
The third of the plotters was Sir Thomas Grey, through his mother Joan Mowbray a descendant of Edward I. His father, also named Thomas Grey, had been one of the allies chosen by Henry Bolingbroke, the future Henry IV, to witness the abdication of Richard II. Thomas Grey the younger had been treated favourably by Henry IV in the sense that he himself had been granted the wardship of his inheritance before he came of age. He was connected to Richard of Conisburgh through the betrothal of his 12-year old son Thomas to Conisburgh´s 3-year old daughter Isabel. Thomas Grey´s involvement in the plot came from, by his own admission, the fact that he wanted to be more rich and “famous” than he was.
If we assume that this was an actual plot, and not only discontent being voiced in an extremely unwise way, the goal was to execute Henry V and his son, the future Henry VI, and replace the king with his own cousin Edmund Mortimer, 5th Earl of March and brother of Conisburghs wife Anne Mortimer who had died in 1411.
Edmund was the great-great-grandson of Lionel of Antwerp, second surviving son of Edward III, through Lionel´s daughter Philippa. The “positioning” of his great-great-grandfather among Edward III´s great number of children actually gave him a stronger claim to the throne than that of Henry V, as he only descended from the third surviving son. Added to this came the fact that Edmund Mortimer and his father, Roger Mortimer (dead 1398), in turn had been considered heir presumptive to Richard II who had had no children of his own.
There had been turbulence between the Mortimer´s and Henry IV. When he had deposed Richard II in 1399 and consequently had parliament proclaim him king and his own son heir apparent, he took the then 8-year old Edmund and his brother Richard into custody with Sir Hugh Waterton at Windsor Castle. Allegedly they were treated good and is said to, during periods, have been brought up with the king´s own children John and Philippa.
It wasn´t a positive turn of events, however, when Edmund´s uncle and namesake, Sir Edmund Mortimer in 1402 was captured by the Welsh rebel leader Owain Glyndwr. Instead of sending men to his rescue or paying a ransom, Henry IV accused Sir Edmund of siding with the rebels voluntarily and confiscated his property.
Sir Edmund then went on to marry Glyndwr´s sister, write a proclamation that declared his nephew the rightful king of England and proceeded to, in collaboration with Glyndwr and the Percy´s (his sister had been married to Henry Hotspur) hatch a plot to free his two nephews from Windsor Castle, something which happened in early 1405. They were quickly apprehended and kept under stricter confinement for the remainder of Henry VI:s reign.
Despite the eventful years of his youth, Edmund Mortimer came to be on good terms with Henry V, who gave him his full freedom when he ascended to the throne in 1413, and maybe that is why, when Edmund Mortimer became aware of the new plot being formed with him as the man to be put on the throne, he went to his king and informed him of everything he knew. No doubt he was also doing his best to avoid ending up on the block.
He revealed the plans to the king on July 31st at Portchester and within day the accused were brought to Southampton to stand trial.
Sir Thomas Grey, who wasn´t a peer, received the trial of a common criminal on August 2nd and was sentenced to being hanged, drawn and quartered. After it was all over, his head was sent to Newcastle.
As they were peers, Henry, Lord Scrope and Richard of Conisburgh was tried by their peers, but it didn´t do them much good as they too were sentenced to death and executed on August 5th. Conisburgh was spared being hanged before being beheaded, and was also the only one of the three who was allowed to be buried together with his head. The head of Lord Scrope was sent to be displayed in York.
Henry V then sailed off to eventually fight the battle of Agincourt at which the older brother of Conisburgh, the Duke of York, was killed. As he had no children of his own, his title went to Conisburgh´s for years old son, as well as the claim held by the Mortimer´s. This he would, years later, when he as Richard Plantagenet, Duke of York, attempted to depose Henry VI.
In 1461, Conisburgh´s grandson, Edward IV, had the parliament declare the sentence against Conisburgh “irregular and unlawful”.
Edmund Mortimer himself was pardoned for nominal involvement in the plot on August 7th and followed the king to France. After the death of Henry V in 1422, Mortimer was appointed to the Council of Regency for the nine month old Henry VI. Mortimer died from the plague in Ireland in 1425, at the age of 33.
Agincourt: A New History – Anne Curry
Richard, Earl of Cambridge (1385-1415) – G.L. Harriss/Oxford Dictionary of National Biography
Henry V and the Southampton Plot of 1415 – T.B. Pugh
Scrope, Henry le (1376?-1415) – James Tait/Oxford Dictionary of National Biography
Scrope, Henry, third Baron Scrope of Masham (c.1376–1415) – Brigette Vale
Mortimer, Edmund (V), fifth earl of March and seventh earl of Ulster (1301-1425) – R.A Griffiths/Oxford Dictionary of National Biography
Portchester Castle – Matthew Folley/Wikimedia Commons
The Red Lion – site of where the trial of the plotters was held
Clare Priory, resting place of Edmund Mortimer – Mym/Wikimedia Commons
Unfortunately images of the actual plotters are less then scarce