In 1796 after being questioned by Napoleon on the status of General Andre Massena's division in the Armee d'Italie and not being able to answer all of the questions put adequately, apparently made up his mind 'to become an authority on military staffs.'
The result of that endeavor, published in Paris in 1800, was the first published staff manual for the French Army. It was entitled Manuel des Adjudans Generaux et des Adjoints employes dans les Etats-Majors Divisionaires des Armees. At the time Thiebault was an Adjutant General, the staff equivalent of a colonel in the line.
The next year an English translation was published in London at the Military Library near Whitehall. In the Introduction to the translation, labeled as 'Advertisement' it reads:
'The great advantages which must manifestly result from a well-conducted Etat-major or staff, are acknowledged in every military country. France, however, seems alone to have entered fully into the system, and to have added experiment of practice to the suggestions of theory.'
'In offering the following translation to the British Army, the Publisher has been principally actuated by a wish to furnish individuals with such general outlines of conduct, as suit all countries and are applicable to all services.'
General Thiebault wrote a second, updated and expanded edition of the staff manual, which was published in 1810 or 1813. It was entitled Manuel General du Service des Etats-Majors which was used by the French army for over twenty years.
There are two highlights of the 1800 manual:
First, the law of 29 October 1790 established a staff corps of 30 officers, the members being named adjutants-general and having the rank of colonel, of which there were seventeen, and lieutenant colonel, of which there were thirteen.-pages 11-12.
Second, the manual gives the organization of the staffs into staff sections, which would be headed under a chief of staff, by an adjutant general.-pages 22-23.
This staff organization delineated the duties of the staff and divided the staff work among the designated staff sections.