- Pontefract Castle 14th Century
- 1393 - At the beginning of May 1393, John of Gaunt invited Thomas Swynford to become one of his chamber knights. On the 12th May, this role was recognised by Richard II who agreed to grant Thomas and his wife, Jane Crophill, an annuity of 100 marks (over £15,000 in today’s money). It is ironic that Thomas would become the gaoler at Pontefract Castle who would be directly attributed with the starvation and murder of Richard II at Pontefract Castle. Thomas would also serve as the constable of the castle.
- Pontefract Castle 15th Century
- 1423 - On 12th May 1423, it was determined that James I of Scotland should be allowed to meet at Pontefract Castle with Scottish ambassadors and those of Henry VI to negotiate his release from captivity and return to Scotland. Safe passage was granted to the Scottish ambassadors on this date also. The first treaty was concluded in London (10th September) with the Bishop and Archdeacon of Glasgow and Abbot of Balmerinoch amongst the Scots’ delegation and the Bishop of Worcester and Stafford, Keeper of the Privy Seal, and Robert Waterton, Constable of Pontefract Castle amongst the English commissaries.
- Pontefract Castle 20th Century
- 1913 - On 12th May 1913, during a balloon ascent and parachute descent at Pontefract Castle for its Whitsuntide gala, the balloon burst injuring a man and young girl.
- Sandal Castle 15th Century
- 1453 - On 12th May 1453, Richard, Duke of York’s (lord of Sandal Castle) lieutenancy of Ireland was taken from him by Henry VI and given to his rival, the Earl of Wiltshire.
- 1480 - On 12th May 1480, Richard, Duke of Gloucester, lord of Sandal, was created Lieutenant-General of the North. Already created Warden of the West March by his brother, Edward IV, to defend England’s border regions with Scotland, he could now call commission of array (raise armies) across most of the north of England and was reinforced in his status as ‘Lord of the North’.