Niels Bohr was born in Copenhagen in 1885. ‘A richly furnished mind’ describes the Christian and Jewish elements of his childhood and upbringing, and his relationship with his fiancée Margrethe Nørlund. It also discusses the influence of the philosophers Kierkegaard and Høffding and the physicists J. J. Thompson, Lord Kelvin, Max Planck, and Albert Einstein on Bohr’s early work and enduring beliefs. This rich background prepared him for the analysis and results of his doctoral thesis of 1911, which exposed serious faults in the largely successful electron theory of metals. He concluded that the faults could not be fixed without fundamental departures from ‘ordinary physics’.