It has been described by the architectural historian Anthony Emery as "the finest surviving example of a semi-royal palace of the later middle ages, significant for its scale, form and quality of workmanship".

Kenilworth was the scene of the removal of Edward II from the English throne, the perceived French insult to Henry V in 1414 of a gift of tennis balls (said by John Strecche to have prompted the campaign that led to the Battle of Agincourt), and the Earl of Leicester's lavish reception of Elizabeth I in 1575.

John of Gaunt spent lavishly in the late 14th century, turning the medieval castle into a palace fortress designed in the latest perpendicular style.

The Earl of Leicester then expanded the castle during his tenure in the 16th century, constructing new Tudor buildings and exploiting the medieval heritage of Kenilworth to produce a fashionable Renaissance palace.

[4][a] Only earthworks and fragments of masonry remain of what was an extensive 13th-century barbican structure including a stone wall and an external gatehouse guarding the main approach to the castle.

[7] The outer bailey of Kenilworth Castle is usually entered through Mortimer's Tower, today a modest ruin but originally a Norman stone gatehouse, extended in the late 13th and 16th centuries.

[5] The outer bailey wall, long and relatively low, was built mainly by King John; it has numerous buttresses but only a few towers, being designed to be defended primarily by the water system of the Great Mere and Lower Pool.

[1] This part of the castle is considered by historian Anthony Emery to be "the finest surviving example of a semi-royal palace of the later middle ages, significant for its scale, form and quality of workmanship".

[15] Although now extensively damaged, these share the same style as the great hall; this would have unified the appearance of Gaunt's palace in a distinct break from the more eclectic medieval tradition of design.

He built a tower now known as Leicester's building on the south edge of the court as a guest wing, extending out beyond the inner bailey wall for extra space.

[37] The external design, with its symbolic towers and, originally, battlements, echoes a style popular a century or more before, closely resembling Kirby Muxloe and the Beauchamp gatehouse at Warwick Castle.

[42] Leicester's intent may have been to create a deliberately anachronistic view across the base court, echoing the older ideals of chivalry and romance alongside the more modern aspects of the redesign of the castle.

[45] In Elizabethan gardens "the plants were almost incidental", and instead the design focus was on sculptures, including four wooden obelisks painted to resemble porphyry and a marble fountain with a statue of two Greek mythological figures.

[49] It resembled Richard II's retreat at Sheen from the 1380s, and was later copied by his younger brother, Duke Humphrey of Gloucester, at Greenwich in the 1430s, as well by his son, John of Lancaster at Fulbrook.

[50] The Pleasance was eventually dismantled by Henry VIII and partially moved into the left-hand court inside the castle itself, possibly to add to the anachronistic appearance.

[53] It appears Clinton had begun to lose the king's favour when in 1130 he was tried for treason, although he was soon acquitted, and when he died in 1133, his son, also called Geoffrey, was only a minor when he inherited his father's estates.

[5] John spent £1,115 on Kenilworth Castle between 1210 and 1216,[54] building the outer bailey wall in stone and improving the other defences, including creating Mortimer's and Lunn's Towers.

John was forced to cede the castle to the baronial opposition as part of the guarantee of the Magna Carta, before it reverted to royal control early in the reign of his son, Henry III.

[65] Papal intervention through the legate Ottobuono finally resulted in the compromise of the Dictum of Kenilworth, under which the rebels were allowed to re-purchase their confiscated lands provided they surrendered the castle;[66] the siege ended on 14 December 1266.

[89] The French aim was to imply a lack of martial prowess; according to Strecche, the gift spurred Henry's decision to fight the Agincourt campaign.

[90] With the mental collapse of King Henry VI, Queen Margaret used the Duchy of Lancaster lands in the Midlands, including Kenilworth, as one of her key bases of military support.

[93] Before his execution in 1553 by Queen Mary for attempting to place Lady Jane Grey on the throne, Dudley had built the new stable block and widened the tiltyard to its current form.

Elizabeth visited in 1566 and 1568, by which time Leicester had commissioned the royal architect Henry Hawthorne to produce plans for a dramatic, classical extension of the south side of the inner court.

[96] However, this proved unachievable, and instead Leicester employed William Spicer to rebuild and extend the castle to provide modern accommodation for the royal court and symbolically boost his own claims to noble heritage.

[108] In the same year Sir Thomas Chaloner, governor (and from 1610 chamberlain) to James I's eldest son Prince Henry, was commissioned to oversee repairs to the castle and its grounds, including the planting of gardens, the restoration of fish-ponds and improvement to the game park.

One wall of the great tower, various parts of the outer bailey and the battlements were destroyed, but not before the building was surveyed by the antiquarian William Dugdale, who published his results in 1656.

[51] Colonel Joseph Hawkesworth, who was responsible for the implementation of the slighting, acquired the estate for himself and converted Leicester's gatehouse into a house; part of the base court was turned into a farm, and many of the remaining buildings were stripped for their materials.

[122] Siddeley, whose tax accounting in the 1930s had been at least questionable, was keen to improve his public image and gave over the running of the castle, complete with a charitable donation, to the Commissioner of Works.

[126] Between 2005 and 2009, English Heritage attempted to restore Kenilworth's garden more closely to its Elizabethan form, using as a basis the description in the Langham letter and details from recent archaeological investigations.

[134] Dr Coutts, Principal Historic Buildings Officer at Archaeology Warwickshire, has also said of the find that "these shots were found pretty much where they would have fallen, [so] we've been able to extrapolate where the siege camps could have been located around the castle.