Bryn was born in London, and after completing a degree at Oxford worked with a friend to set up Latch. A self-help housing organisation in Leeds, Latch enables young homeless people to renovate derelict housing and house themselves. The organisation won the Community Enterprise Award for homelessness in 1994.
Bryn moved from Latch to help others set up similar community development organisations. This work took him to Northern Uganda, South Sudan, Rwanda, Burundi, Kenya and Palestine, where he assisted community-led efforts to address violence and war, and uphold human rights. In 2016 Bryn completed a PhD from Bradford University on justice in violent conflicts.
Alongside his peacebuilding research, Bryn was employed as executive secretary of the Polden-Puckham Charitable Foundation for ten years. There he worked to fund efforts to address violent conflict and environmental breakdown including climate change. He was appointed part-time to the Frederick Mulder Foundation in June 2019.