“He was an English nobleman, one of the few who remained loyal to Richard II to the very end.

He was the son of Sir John Montacute and Margaret de Monthermer. His father was the younger brother of William Montacute, 2nd Earl of Salisbury. His mother was the granddaughter and heiress of Ralph de Monthermer.
As a young man Montacute distinguished himself in the war with France, and then went to fight against the pagans in Prussia, probably on the expedition led by the Henry Bolingbroke (the future Henry IV of England).
He was summoned to parliament in 1391 as Baron Montacute.
Montacute was a favorite of the king during the early years of the reign of Richard II. He accompanied the king during his expeditions to Ireland in 1394 and 1395, and as a privy councilor was one of the principal advocates of the king's marriage to Isabella of Valois. During the trips to France associated with the marriage he met and encouraged Christine de Pisan, whose son was educated in the Montacute household.
With the death of his mother around this time he inherited the barony of Monthermer and its estates.
Montacute was a prominent Lollard, and was remonstrated by the king for this.
In 1397 he became Earl of Salisbury on the death of his uncle. He continued as one of the major aristoratic allies of the king, helping to secure the fall of the Duke of Gloucester and the Earl of Warwick. He persuaded the king to spare the life of Warwick. He received a portion of the forfeited Warwick estates, and in 1399 was made a Knight of the Garter.
Early in 1400 he went to on a successful mission to France to prevent the proposed marriage of Henry Bolingbroke and a daughter of the Duke of Berry. In May he again accompanied Richard II on an expedition to Ireland. When news reached them of that Bolingbroke had returned to England, Montacute was sent to Wales to raise opposing forces. When these deserted Montacute advised Richard to flee to Bordeaux. Instead Richard was imprisoned, Henry took the throne, and in October Montacute was arrested along with many of Richard's former councilors, and held in the Tower of London.
Montacute had to answer charges related to the arrest and subsequent death of the duke of Gloucester in 1397. Eventually he was released, due to the intercession of king Henry's sister Elizabeth, Countess of Huntingdon.
Not long after his release Montacute joined with the Earl of Huntingdon and others in a plot to kill king Henry and restore Richard II. After the plot failed he was caught and executed. His eldest son Thomas eventually recovered the earldom, though the attainder against John Montacute was not reversed until the accession of Edward IV in 1461.
Montacute married Maud Francis, daughter of Adam Francis, who was a citizen of London.
(Wikipedia)
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