Hey Erik and Bingeling,
thanks for the reply! Regarding your questions:
Yes, this was a completely unmodded game. Actually my first "real" one (besides from playing tutorials and a first oh I did everything wrong test game), so I might understand / do a lot of things still wrong.
Yes, I was pretty late in the game. I can check the exact date when I am home, but regarding tech I had almost all major components researched to the biggest type (but not all the improvements). I started Pre-Warp, but I don't know how far these Empires where regarding technology. Is there a way to check that? (I hope there is still a savegame from the time before I defeated them). I admit I did not check the exact build of those ships, but they were way behind in numbers regarding firepower and ship size. (But they had something like 20 Explorers ;) )
I knew what was coming, I was just wondering if it was supposed to be that massive and kind of, well, unhandable (not exactly regarding power, but more from the sheer number of events). Especially after the cakewalk with the other empires. But well, if that's how it supposed to be, I will be prepered. Next time ... :D
Thanks for the suggestions, I'll start over with a higher difficulty level, the mentioned AI mod and a bit more aggressiveness (Is the aggressiveness level in regards towards the player or also against the other AI empires? Because the AI fancied some wars against each other, but left me in peace, even if I did nothing regarding diplomacy).