In Wrath of the Lich King it is item level 245, requires level 80 and is named Worldbreaker Headpiece. In MoP Classic it is item level 232 and requires level 80.
Read from the World of Warcraft client build files.
How Conqueror's Worldbreaker Headpiece Compares
Who It Suits
Mail is the armor type Evoker, Hunter and Shaman wear. With Agility or Intellect, Conqueror's Worldbreaker Headpiece suits Beast Mastery, Marksmanship and Survival Hunter; Elemental, Enhancement and Restoration Shaman; Devastation, Preservation and Augmentation Evoker.
Transmog Sets
Conqueror's Worldbreaker Headpiece is part of the transmog set Conqueror's Worldbreaker Regalia (Shaman only). The other 16 pieces:
Items Numbered Next to Conqueror's Worldbreaker Headpiece
Blizzard numbers items as they are created, so the named items next to ID 46201 (46196 to 46206) were usually added in the same batch as Conqueror's Worldbreaker Headpiece: the same quest line, zone, vendor or reward set.