The Historical Thesaurus began in 1964 when Professor Michael L. Samuels announced in an address to the Philological Society that he and his colleagues in the English Language Department of Glasgow University had embarked on the task of producing a comprehensive study of the English vocabulary, the first ever notional classification on historical principles of any language. After Professor Samuel’s retirement supervision of the completion of the project was undertaken by Professor Christian Kay.

The completed work contains nearly 800,000 meanings, organised into more than 236,000 categories and subcategories and collected together in two substantial volumes. Entries are arranged in a detailed thematic structure, thus offering a groundbreaking analysis of the language, as well as a chronological list of synonyms, based on the Oxford English Dictionary to which these volumes are an invaluable complement.

The impact of the new thesaurus will reach far beyond the study of language offering fresh perspectives to scholars in many other fields including anthropology, history and culture. It was published on 22 October 2009.