After reading for a degree in Classics at Oxford I worked in television for 15 years, before studying Anglo‑Saxon, Norse, and Celtic in Cambridge, where I gained a BA (Aff.), MPhil and PhD in the department, working on the manuscript transmission of Pelagius’ Letter to Demetrias. I was a British Academy Postdoctoral Fellow 2012-15. My research has focused on Pelagius and Faustus of Riez, two British authors of the fifth century who wrote in Latin; overall my interest lies in the history of the peoples of the Insular milieu from the fifth century to the Conquest.
I have published on St Patrick, Columbanus, Pelagius, and the manuscript transmission of Pelagius’ works.
My first book, The myth of Pelagianism, was published by the British Academy in 2018.
I teach Celtic history, which encompasses the history of the Brittonic speaking peoples and the history of the Gaelic speaking peoples, as well as Latin and Medieval Welsh.