Down to the end of the nineteenth century, the comprehensive historical lexicon of classical Latin was only a dream; its realization began in 1893 with the decision by the five German-speaking academies then in existence to compile the Thesaurus linguae Latinae as a joint project, the moving spirits being Eduard Wölfflin and Theodor Mommsen; in 1894 the practical work began in Göttingen and Munich with the assembling of the material.
This progressed according to plan to the point where, in 1899, the actual work of compiling the articles could begin in Munich, which has been the home of the project ever since; the first fascicle appeared in 1900.
Even in the earliest years, however, it became apparent that – as with all lexica on this scale – both the difficulties and the time needed for completion had been drastically underestimated. Suitable methods of compilation could of necessity only be developed from practical experience and had to satisfy ever rising expectations, especially in the areas of Christian texts and late Latin. As a result, during the fifteen years originally estimated for the whole project, the Thesaurus had got only as far as the first half of the letter D.
Time and again, the political catastrophes of the twentieth century brought the work to a standstill, so that it was necessary to start on a new administrative footing with the founding of the International Thesaurus-Committee in 1949. At present the lexicon is a communal undertaking of 31 academies and learned societies from both within Germany and abroad. By now it is more than two-thirds complete.
Deliberately with the programmatic subtitle "as preparatory work to a Thesaurus linguae Latinae" (from 1900: "in addition to the Thesaurus linguae Latinae"), Wölfflin published 15 volumes of the "Archiv für lateinische Lexikographie und Grammatik" from 1884 to 1908. With a network of hundreds of philologists, questions and methods were played through, many questions concerning the organization and working methods of the planned thesaurus were discussed and approaches to solutions were pointed out. Much of what today naturally belongs to the Thesaurus was decided at that time and so it is definitely worth taking a look at the articles in the archive.