The "Lexicon Gregorianum" constitutes the most comprehensive Greek-German dictionary ever, of the language used by Gregory of Nyssa. It is the result of more than three decades of dedicated scholarly research. It is, and will be for the foreseeable future, the only dictionary available specifically addressing the vocabulary of late classical Greek. Far from being a simple word list, this seminal reference work documents Gregory's complete vocabulary, taking account of the syntax, meaning and connotations of every occurrence of a key word in his writings. Volume One, published in May 1999, of the Lexicon contains 2,370 entries covering the letter ?. Volume Two covers the letters ? to ?. The complete Lexicon will comprise 7 volumes, totalling more than 13,000 entries.