The British National Corpus (BNC) is a 100 million word collection of samples of written and spoken language from a wide range of sources, designed to represent a wide cross-section of British English from the later part of the 20th century, both spoken and written. It is one of the first generation of monolingual, synchronic, general, representative corpora of its size, and led the way for other national corpora. It was created by a consortium of academic partners and publishers, with funding from the Department of Trade and Industry in the UK. This posters reflects on a number of lessons learning in more than thirty years, in terms of corpus representativeness, modes of access to the corpus, licensing, and managing the transition from a contemporary synchronic corpus to a historical corpus.