In 1991, just as Jonathan Sacks was acceding to the post of Chief Rabbi, the United Synagogue, the largest synagogal institution in British Jewry, commissioned a report entitled A Time for Change . This report identified the significant difficulties in which many of the Orthodox institutions of British Jewry found themselves: the United Synagogue itself, the Chief Rabbinate, and the Bet Din - its religious court. It suggested that the root cause of the problems was a shift away from ‘minhag Anglia, a celebration of the twofold blessing of being Jewish and British’. This work examines the thought and influence of the three Chief Rabbis whose terms in office have begun and ended during the twentieth century. It follows the theological shifts that have occurred amongst the religious leadership of Orthodox Judaism in Britain and assesses the influence of factors such as immigration and the so-called ‘Jacobs Affair’ in effecting these changes. The Jewish community in Britain provides a model of a religious minority group’s attempt to secure its survival in the midst of a host society that espouses alternative values derived either from secularism or an alternative religious system.Through an in-depth analysis of the theology of Chief Rabbi Joseph Herman Hertz, this work identifies a paradigm that was established for Jews in Britain of a strong and confident Orthodoxy that champions interaction in the host society. The Chief Rabbinates of Israel Brodie and Immanuel Jakobovits were each influenced in different ways by the burgeoning influence of alternative models for Orthodox Judaism. This work considers how this facilitated the displacement of the community’s fervour for unity with religious polarisation; and analyses how its religious leadership adopted a theology which seemed to call on Anglo-Jewry to forsake its ideology of meaningful interaction to secure its religious identity.