This is the first part of a two volume analysis of British theatre censorship from 1900 until 1968, based on previously undocumented material in the Lord Chamberlain's Correspondence archives. It covers the period before 1932, when theatre was widely seen as a crucial medium with the power to shape the future of society, determining what people believed and how they behaved. Where previous interpretations, based on more limited evidence and topics, have often constructed the Lord Chamberlain's Office either as an annoying but amusing irrelevance, or as dictatorial in its unchanging...