Order of weapons fire / damage?

[AMF]

OK, so a related question that I have always puzzled over and never fully answered:

who fires first in a (strategic) combat?

I know that if one side is at a WP and the other side warps in, then the defender goes first...

but I recently had a combat where I was the defender and it really looked like none of my guys fired first, and, well, I lost my entire fleet (and it looks like I am going down in flames becuase of it)...

so...who first first?

thanks,

Alarik