What would had happened, had the helveti defeated Ceasar so throughly that he and his troops were all killed at the first battle of the gallic wars ?

  • The Romans would have waited a few years and then sent another army. Other armies sent to Gaul before Caesar were slaughtered in their entirety before, it just made Rome wait a bit.

    Wouldn't the gallic wars be stopped right there, as this war was Cesar idea, not that of the Senate ? 

    Roman armies had tried to invade gaul before. There's an invasion during the 2nd punic wars that ends badly, I can't find the link, and there's also this: Battle of Arausio - Wikipedia Rome had designs on Gaul for centuries, Caesar was special because he succeeded where others had failed.