I have just read the etymology of the word; quite fascinating indeed. But I would also want to know when this word was introduced into the language. My guess is somewhere in the Middle Ages, but I would really like to know for sure.
If the etymology you've read is “from bacca (berry) and laureatus (covered in laurel)”, that was probably invented after the fact. Laureatus might have influenced the ending of the word but bacca was probably made up to explain what remained at the beginning. The Trésor de la langue française has a more researched (though not absolutely certain) history.
The term probably evolved from the Medieval Latin baccalarius, also attested as baccalaureus. The origin of this term is contested. One hypothesis is that it is derived from bacca from the Latin vacca (cow), hence baccalarus farm-hand, then lower-status person who might be an apprentice to a knight, hence knight in training. Another hypothesis is that a baccalarus is a person wielding a baculum (stick), again a knight in training.
Around the 16th century, it seems that the word evolved to bacchilaureatus or baccalaureatus, under the influence of laureatus, after it had been used in universities. It came to mean a junior student and a junior diploma. Note that universities at this time still used Latin, not French. Baccalauréat is the French form that appeared in the late 17th century.
A similar word bacchalariatus or bachalariatus, meaning a junior member of a liturgical choir, probably influenced the university term as well. I don't know the origin of this word (it may or may not be related to the knight-in-training meaning). A bachalariatus diploma is attested in the 16th century.
The etymology of this and related words is discussed at length (in Latin) by Du Cange, but beware that his conclusions have been contested.
In the middle age, XIII century at the University of Paris.
The word come from the latin word "bachalariatus" which was the first rank in the process for becoming a knight.
The first "bac" was in 1808.