When were spaetzels invented ?

Answer 1

Neither the etymology of the word "spaetzle" nor the
culinary history of the dish spaetzle is clear.

As regards the etymology of the word "spaetzle". According to
Lerch, there are three possible explanations, roughly:
(1) dumplings were called "Spatzen" because of some kind of similarity in form with sparrows, from there the "spaetzle" ('little sparrows') were derived;
(2) the word is derived from italian spezzare; spezzato 'to cut to pieces', because the dough is cut to pieces before it is boiled; (3) there might be some connection to italian pasta or french pate.

Now, the culinary history of spaetzle is difficult to track down for two reasons.

First, because the words "spatzen", "spaetzle", "knoepfle" etc. were often used for quite different things. There are clear examples from the 18th century that "Spatzen" or "Knoepfle" denoted dumplings or little dumplings. It is not clear how, when and if at all the development from Spatzen 'dumplings' to spaetzle 'the special type of noodles' happened.

Second, there is the problem of the interpretation of pictorial
representations one has to rely on. Lerch tells us that a 19th century professor (Sachsse) concluded from a picture in a
'Sachsenspiegel'-manuscript (a very important juridical text), that the suebian duke was represented with a utensil for making Knoepfle or Spaetzle and thus was an example for an early Spaetzlesschwab (a suebian who likes spaetzle).

Now, the utensil looks like sort of a shovel which is hardly a typical utensil for preparing spaetzle. Anyway, according to Lerch, Prof. Sachse made up the myth of the suebian eating
spaetzle since the middle ages

To conclude: Lerch quotes no evidence that there were spaetzle in the Middle Ages. To the contrary: he describes how the myth of the medieval 'spaetzlesschwab' could arise.

It looks likely that spaetzle with their specific preparation are a 'late' dish from the 18th or even19th century.