Hearing the news, Edward I gathered his forces to unseat the newly named prince.
Sensing a losing effort, most of his countrymen gave up hope of continuing the Gwynedd regime.
In June 1283, Gwladys was arrested with her father, mother, brothers (Llywelyn and Owain), and sisters.
Gwladys was dispatched to the Gilbertine convent in Sixhills, Lincolnshire, as a young child.
Edward I ordered annual payment of 20 pounds for Gwladys's upkeep at the Sixhills convent, where she spent the remainder of her life.