2026 sees the centenary of the publication of Mill Stephenson’s List of Monumental Brasses in the British Isles, a work that is still the sole complete inventory of all British monumental brasses. Stephenson was a Fellow of the Society of Antiquaries of London, and it was the Society’s own collection of brass rubbings that provided the essential foundation for his work. Stephenson’s project was a collaborative one that drew heavily on the endeavours of other like-minded antiquaries, and the Society’s Inner Library was the nerve-centre of his operation. Stephenson published extensively, and he left many of his papers and collections to the Society. Together, these sources allow us to build a picture of his working methods and the stages from which the List was to emerge. The article will look afresh at Stephenson’s career, about which hitherto little has been written, looking especially at his private life and the range of his acquaintances, his List and the role of the Society in its creation. It will further attempt an evaluation of his scholarly achievement, considering both his strengths and weaknesses as a scholar, and it will conclude with some reflections on how the listing of brasses has evolved since his time.