26/12/2025
Murder at Abergavenny Castle on Christmas Day 1175.
Seisyll ap Dyfnwal was a Welsh Lord in the Kingdom of Gwent and a brother-in-law of the Lord Rhys, King of Deheubarth. On Christmas day 1175, along with his eldest son Geoffrey and other Welsh leaders from the area, Seisyll was invited to Abergavenny Castle by Norman Baron William De Braose to try and resolve their differences following a period of conflict. However once inside the castle walls, they were cut down without mercy and De Braose and his men then rode out to Seisyll's home where they murdered his seven year old son, Cadwalladr and captured his wife.
The effect of De Braose's actions was to have a negative impact on Anglo-Welsh relations for generations to come, with the de Braose family name becoming a byword for dishonourable dealing and De Braose himself earning the nickname the 'Ogre of Abergavenny'.
In 1182, Hywel ap Iorwerth the Welsh Lord of Caerleon avenged the death of Seisyll by storming Abergavenny Castle and putting De Braose to flight. De Braose later died in exile.
