Historians have generally considered Clarence's fall from power to have been the direct result of his abuse of his feudal authority and usurping of the King's justice.

[7] Clarence was also jealous of the power of his and Edward's younger brother, Richard, Duke of Gloucester, while the Woodvilles encroached on his Marcher lands, where they were building a regional hegemony.

[24] It is curious, suggests the medievalist John Ashdown-Hill, that the deaths of Isabel and her son occurred at such different lengths of time following their supposed ingestion of poison.

Ashdown-Hill explains this by suggesting that October was actually a scribal error for December, in which case she died the day, possibly a few hours, after her son.

For example, the report of the dumping of William de la Pole, Duke of Suffolk's murdered body on the Dover shore on 2 May 1450 arrived in London on 4 May.

[38] Another man, Sir Roger Tocotes, was accused by Clarence of aiding, abetting and harbouring the criminals,[18] and possibly of orchestrating the whole plot.

[18] The Parliament Roll later recorded thatDiverse of the same Jurre, after the said Judgment goven, came to the seid Ankarette, havyng grete remorce in their consciens, knowyng they hadde goven an untrue Verdyt in that behalf, humbly and pituously asked forgefnes thereof of the seid Ankarette...[47]Both Twynho and Thursby were "drawn at the horse's tail" through Warwick to their execution.

[42] Twynho was accused of committing the crime while she and Isabel were at Warwick Castle—thus allowing the Duke to try her there—although contemporaneous evidence indicates that the Duchess was at Tewkesbury until mid-November.

[50] He suggests that the Duke was guilty of embracery at the least, and Twynho's original arrest and detention was probably illegal also since the royal commission later referred to "the unlawful taking of Ankarette through three shires".

[52] In what the scholar Cora Scofield calls "revenge ... in a manner scarcely less extraordinary" than the Duke's own,[53] and what may have been a subtle warning to Clarence,[50] the King instructed a commission of 17 lay magnates to investigate the judicial proceedings.

Investigation swiftly led to an Oxford University clerk called John Stacy, a prominent alchemist,[54] alleged astrologer and magnus necromanticus, or great sorcerer.

[55] Stacy—under acerrimum examen, literally, "severe examination" (i.e. torture)[56][46]—in turn implicated Thomas Burdet of Arowe,[53] a member of Clarence's household.

[60] Blake was reprieved after a petition from the Bishop of Norwich,[61] but Burdet and Stacy, still protesting their innocence, were taken to Tyburn the following day and hanged, drawn and quartered.

[46] On learning of this writ[46]—which removed the danger of his arrest by the Duke—Sir Roger Tocotes surrendered himself to the Marshalsea Prison; he was later acquitted of complicity in the death of the Duchess.

[63] Accompanied by the Minorite preacher Dr John Goddard, the Duke interrupted a royal council meeting while the King was in Windsor.

Goddard was the priest who had publicly, and vehemently, advocated Henry VI's return to the throne in April 1470 at St Paul's Cathedral, after Edward had been forced into exile by Warwick and Clarence.

[note 3] While this match was never likely to come to fruition—Mary was already engaged to Maximilian, son of the Holy Roman Emperor—it furthered the Duke's discontent:[31] Rivers was a Woodville, and to Clarence the whole family was an enemy.

[74] In late June 1477, Clarence was arrested and imprisoned in the Tower of London on charges of usurping royal authority, or "violating the laws of the realm by threatening the safety of judges and jurors", states Bellamy.

Except for some minor business, this parliament—to which a large number of both royal and Woodville clients had got themselves elected[74]—had been called expressly to attaint him of high treason.

He was probably aided by several MPs connected to the case, who included John and William Twynho—sitting for Gloucester and Dorset respectively—and Robert Tocotes, Sir Roger's brother.

In his will,[84] proven in 1485,[85] he left a silver cup to the Abbess of Shaftesbury inscribed venerabilis dux Clarencie ex sua benevolencia michi dedit ("given me by the Duke of Clarence in his benevolence").

The folklorist George Kittredge called it a cause célèbre,[46] while more recently Carpenter has described it and the subsequent arrests and execution of Burdet and Stacy as being of "considerable significance" at the time.

[4] Ross called it a "scandalous demonstration" of the misuse of magnate authority,[87] while Rosemary Horrox cites Clarence's over-awing of the jury as a "classic symptom of bastard feudalism".

He also argues that there is a contradiction, if Clarence was both sufficiently disturbed to believe in Twynho's guilt but sensible enough to recognise the weaknesses in the case and to stage-manage evidence.

[33] That previously loyal household servants such as Twynho and Thursby, and intimates as Tocotes, no longer felt the Duke's service provided security or the prospect of promotion is apparent.

[8][7] Compared to Clarence, the Woodville family, headed by Queen Elizabeth, had grown powerful, and with the royal children growing up, their households were also increasing.

Ankarette Twynho was unemployed after Isabel's death and would have presumably accepted employment with any lord or lady, while Tocotes had become Master of Game for the Queen.

[16] Hicks suggests that the possible disintegration of his affinity at the hands of his brother and in-laws was sufficient to drive Clarence to seek revenge;[16] it also demonstrated "a talent for swift and ruthless action" in him.

[99] Bellamy has argued that Clarence's wielding of the legal machinery for personal motives only caused the subsequent outcry it did because he was out of royal favour and with waning prospects.

[101][16] On this phenomenon, Croyland comments how You might then have seen (as such men are generally to be found in the courts of all princes), flatterers running to and fro, from the one side to the other, and carrying backwards and forwards the words which had fallen from the two brothers, even if they had happened to be spoken in the most secret closet.