TDW was formed back mid-TBC mostly from Bad Moo Rising members who were more raid dedicated and looking for something more. We cleared all content up to Felmyst but around that time many members were looking for a break from the game as the upcoming expansion was coming out soon.
TDW laid dormant as the remaining members sought out other guilds to raid with. Near the end of Wrath a few remaining members decided to get TDW back and raid casually in Cataclysm. After gathering up some ex-members and a few new ones we finally got started raiding in this expansion and have done quite well.