Tension between Edward I and Llywelyn came to a head over the building of Dolforwyn Castle in 1273. Their rival points of view are given in this letter from Llywelyn, and a manifesto written three years later on behalf of Edward I.
To see Dolforwyn Castle, visit Castlewales.
Catalogue reference: SC 1/19 no. 22 and SC 1/55 no. 30b
Document 1 | Document 2