I just saw http://www.xbox360achievements.org/game/elder-scrolls-v/achievements/ page outlining achievements on the 360 for Skyrim, and one is "become a member of the Circle". I'm wondering what people think this is, is it perhaps another faction?

Mhhmm Good Pickup not too sure probly a sub faction.

It's in-between the "join the Companions" achievement and "finish the Companions Quest line" achievement, so I'm assuming it's an elite group in the Companions Guild.

So sub-faction, part of the Companions.

Ah, yes, I noticed that all the factions had 3 questline achievements a bit after I posted this, so this is one of those. Shame there aren't more factions (unless joining some other, minor factions does not give you any achievements) but being able to take sides in the war is pretty cool.

*looks at first and second page* :facepalm: