That's the Arachnos Rising badge - part of it is Warburg so heroes can get a fifth of it.
You can also get a quarter of the Swashbuckler badge in Siren's Call if you really want.
Edited: My thought drifted on the wrong badge (Igor is correct).
Thought the badge in question was the "new" history bar of Nemesis. (That one is a bug)
Serves me right for posting when not awake.
Lady Arete on Unionhandbook
My Excel Badge tool
Thanks, got this answer in-game as well... annoying that you can get a part of it. But what possibilities when going rouge goes live. 
I thought I had all the history badges and according to City Info Tracker I do... but looking at my character I have one unfinished history badges (1/5) with this description:
Learn the history of lord recluse's arrival to the rogue islands
Uhm. What badge is that? I cant find any info about it anywhere... or is it even a villain badge? Well, as said I can't find any info about it.