I was bewildered for a moment, because I thought the Black Arcs were made post War of Beard.
Then I recalled that the Dwarves didn't actually go to Ulthuan, so the forts on Ulthuan were probably anti daemon, not anti dwarf.
Derp. Who thinks of daemons when someone says siege?
Apparently, we should.
So, your avatar is an imposer pretending to be Buckethead. That's heresy. Witness the glory of the real Buckethead and repent. https://youtu.be/dyQJH615KwA