Rows shaded amber mark events tied to a major war, siege, or battle.
| Date | Event | War / Conflict |
|---|---|---|
| 1066 | William the Conqueror crosses the Thames at Wallingford after Hastings; Wigod, the town's Saxon lord, welcomes him rather than resisting. | Norman Conquest |
| 1067–71 | Robert D'Oilly builds Wallingford Castle on William's orders; 8 houses (including high-status Saxon homes) demolished per Domesday, absorbing part of the existing Saxon burh's defences. | — |
| 1086 | Domesday Book records the castle's toll on the town: 8 of 276 properties destroyed, street grid disrupted. | — |
| 1130s | The original timber castle is rebuilt in stone — a shell keep and curtain wall — traditionally credited to Brian FitzCount, shortly before the Anarchy. Some specialists argue this overstates a single rebuild; the true process may have been slower, incremental masonry upgrades. | — |
| 1135–53 | The Anarchy: Wallingford holds for Empress Matilda under Brien FitzCount, never falling to King Stephen despite repeated sieges. | The Anarchy |
| 1145–46 & 1152 | Stephen builds counter-castles to blockade Wallingford — chiefly at Crowmarsh Gifford, plus Brightwell, South Moreton and Cholsey — rather than storming it directly. | The Anarchy |
| 1153 | Henry (future Henry II) relieves Wallingford, besieges Stephen's Crowmarsh fort in turn; standoff produces the Treaty of Wallingford, settling the succession. | The Anarchy |
| 1155 | Henry II grants Wallingford a Charter of Liberties as reward for its loyalty — one of the oldest such charters in England. | — |
| 1191 | King John (then a prince) seizes the castle during his revolt against Richard I; forced to surrender it. | — |
| 1199 | King John reclaims the castle on becoming king. | — |
| 1215–17 | King John repairs the moats, garrisons the castle heavily, and uses it to hold prisoners; on 17 Oct 1216, two days before his death, sole custody is handed to his son Richard (future Earl of Cornwall), continued by Henry III. War itself ends Sept 1217 with the Treaty of Lambeth/Kingston — a win, on balance, for the young king's regency government. | First Barons' War |
| 1231 | Henry III grants the castle to his brother Richard, Earl of Cornwall, who rebuilds it into a lavish residence. | — |
| 1260s | Second Barons' War: Simon de Montfort seizes the castle after his victory at the Battle of Lewes, briefly imprisons the royal family there. | Second Barons' War |
| 1307 | Edward II's favourite Piers Gaveston holds a huge tournament at the castle. | — |
| 1323 | Contrariant prisoners Maurice, Lord Berkeley and Hugh Audley the Elder are held at Wallingford Castle (formerly Piers Gaveston's); a plot to free them is uncovered. | — |
| Nov 1326 | Isabella of France, having already won her invasion (landed Suffolk, Sept 1326), issues her reward for Hugh Despenser the Younger's head from Wallingford Castle. | Invasion of England, 1326 |
| 1328 | Roger Mortimer, now Earl of March and de facto ruler of England, is granted custody of Wallingford Castle itself as part of his new earldom. | — |
| 1330 | Edward III, now of age, stages a coup at Nottingham Castle; Mortimer is arrested and executed at Tyburn, ending his 3-year de facto rule. | — |
| 14th century | Edward the Black Prince makes Wallingford his principal residence; his father King Edward III fixes the castle to the title of Duke of Cornwall. | — |
| 15th century | Constables include Thomas Chaucer (the poet's son) and William de la Pole, Duke of Suffolk; Owen Tudor's guardianship of young Henry VI here leads to his liaison with Katherine of Valois — origin of the Tudor dynasty. | — |
| 1502 | The future Henry VIII inherits the castle but prefers his manor at Ewelme, leaving it without a resident lord. | — |
| 16th century | Mary I strips lead from the castle for use at Windsor; ongoing stone-robbing follows as the site declines further. | — |
| 1642–46 | English Civil War: castle refortified as a Royalist stronghold under Colonel Blagge, part of the ring defending Charles I's Oxford headquarters. | English Civil War |
| 1646 | 4 May – 27 Jul Parliamentary siege under Sir Thomas Fairfax; Colonel Blagge surrenders on honourable terms after Oxford's fall leaves Wallingford isolated. | English Civil War |
| 1652 | Cromwell's Council of State orders the castle slighted (deliberately demolished) to remove any future military value. | English Civil War (aftermath) |
| 1837 | A mansion house is built within the castle grounds. | — |
| 1972 | The 1837 mansion is demolished; grounds progressively opened to the public. | — |
| 2022–ongoing | Historic England funds repairs to the College of St Nicholas ruins; site remains on the Heritage at Risk Register. | — |