Book excerpt: Fascinating and authoritative of Britain's royal families from Henry VIII to Elizabeth I to Queen Victoria, by leading popular historian Alison Weir 'George III is alleged to have married secretly, on 17th April, 1759, a Quakeress called Hannah Lightfoot. If George III did make such a marriage...then his subsequent marriage to Queen Charlotte was bigamous, and every monarch of Britain since has been a usurper, the rightful heirs of George III being his children by Hannah Lightfoot...' Britain's Royal Families provides in one volume, complete genealogical details of all members of the royal houses of England, Scotland and Great Britain - from 800AD to the present. Drawing on countless authorities, both ancient and modern, Alison Weir explores the crown and royal family tree in unprecedented depth and provides a comprehensive guide to the heritage of today's royal family – with fascinating insight and often scandalous secrets. 'Staggeringly useful... combines solid information with tantalising appetisers.’ Mail on Sunday