In Wrath of the Lich King it is item level 245, requires level 80 and is named Siegebreaker Legplates. In MoP Classic it is item level 232 and requires level 80.
In the Appearances collection, Conqueror's Siegebreaker Legplates is listed as Boss Drop. Appearance ID: 11563. 3 other items wear the same appearance:
Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Conqueror's Siegebreaker Legplates Compares
Who It Suits
Plate is the armor type Death Knight, Paladin and Warrior wear. With Strength or Intellect, Conqueror's Siegebreaker Legplates suits Arms, Fury and Protection Warrior; Holy, Protection and Retribution Paladin; Blood, Frost and Unholy Death Knight.
Items Numbered Next to Conqueror's Siegebreaker Legplates
Blizzard numbers items as they are created, so the named items next to ID 46150 (46145 to 46155) were usually added in the same batch as Conqueror's Siegebreaker Legplates: the same quest line, zone, vendor or reward set.