A huge siege happened. I'll try to make this simple:
-bad points: several dead civilians, most of which were too stupid to stay away from the spike traps on repeat or the crossbowgobbos. 3 dead soldiers, among which the captain of the guard, who rushed towards the enemy with his artifact crossbow instead of shooting them, therefore turning into a porcupine (as well as an elite marksdwarf, the dumbass got a promotion for nothing... he never was very bright anyway) before death. Lots of stuff to clean up. 3/4 of the war dogs of my thermonuclear wardog bomb, if no more, died without inflicting any damage.
-good points: my best soldier is unharmed (that badass hammerdwarf lacks a lower left arm since Armok knows how long; he's the dad and only parent of our mayor so I'll take good care of them both...). This time, no enemy even approached my entrance nor destroyed my precious windmill power system. Also, no flying mounts = no stupid gobbo getting inside because I haven't entirely closed all entrances from my megaproject. The war dogs were extremely useful into forcing the opponents to waste most of their ammo. All cage traps were succesful. My special bridge trap sent... about 20 gobbos to their spiked doom underneath; less than half are still alive, including a spearmaster, plus the last crossbowgobbo of the siege that dodged retardedly a dwarf into the garbage pit (I LOVE THIS TRAP SO MUCH NOW) => I'm gonna give my veterans a much-deserved Christmas as the survivors are horribly crippled and devoid of weapons. While many civilians died, that means the latest migrant wave has had its negative effect cancelled by bloody, bloody death.
So, all in all, a pretty succesful siege. Today's lesson: do not understimate the power of the bridge. I shall use it to my advantage.