Well it wasn't THAT long long ago.
It was actually 475AD and down around Londinium the Dragons,their allies the Reptile People,and the Angle and Saxons and King Arthur and his folk had just signed a Peace Treaty
to end a dispute between the sentient races.
So the last thing they were expecting was the arrival of a giant Space Ark with hostile liens aboard that wanted to lob a asteroid at England.
Heck,folk were still recovering from the pullout of the Roman Empire army in 410.
So there the Terrans all were signing their Peace Pacts when the wine and mead glasses began to rattle and then there it was,blotting out the Sun
a giant orb up in space.
"Damn" said Merlin and Queen Guinivere at the same time
The Reptile People,always a paranoid lot at the best of times,suddenly began hissing and shouting
"Betrayl Betrayl Trickery from the Human Knaves"