 Counter-balancing all this, he is said to have been involved in the signing of Magna Carta in 1215 (though perhaps reluctantly), founded Mottisfont Abbey, a house of Augustinian canons six miles from Ashley (to whom he donated St Mary's Church, Ashley ), and ended his days in 1226 as a Cistercian monk.In 1200 King John granted Briwere a licence to crenellate a number of castles, including, in Hampshire, one at either Stockbridge or Ashley (at Briwere's election) .Since there is no castle in Stockbridge, the reference to Stockbridge may conceivably have been to the ancient hill fort above that town on Stockbridge Down, at Woolbury.