This introduction presents an overview of the key concepts discussed in this book. The book presents an analysis of Britain's Chief Rabbis over the ninety years between 1880 and 1970, and the impact they made upon Anglo-Jewry's religious character. It begins with the study of Nathan Marcus Adler, Chief Rabbi from 1845, and it then explores how in 1880 Hermann Adler became Delegate Chief Rabbi on his father's semi-retirement to Brighton. The book further examines the second Chief Rabbi, Joseph Herman Hertz, appointed in 1913, who held the office until he died in 1946. It also explores what Hertz meant by 'progressive conservatism' and assesses what Hertz's policies implied about his theology. The book finally examines Louis Jacobs Affair, and the election of Immanuel Jakobovits, Chief Rabbi 1967-1991, and his early years in office.