William is a specialist in the genealogy of royal, aristocratic and historical families. He was educated at the University of Oxford, and the University of Cambridge. He is the Executive and Royal Editor of Burke's Peerage and Gentry, a Director and Trustee of the Society of Genealogists, and Vice Chairman of The Association of Genealogists and Researchers in Archives. He was appointed a trustee of The Foundation for Medieval Genealogy in 2008.

William began his interest in genealogy as a five-year-old boy while listening to the anecdotes and reminiscences of his father. He has developed that interest in the ensuing quarter of a century to become a distinguished genealogist. He is an authority on the royal families of Europe. His other interests include architecture, gardens, music and travel.