In Wrath of the Lich King it is item level 245, requires level 80 and is named Aegis Legplates. In MoP Classic it is item level 232 and requires level 80.
Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Conqueror's Aegis Legplates Compares
Who It Suits
Plate is the armor type Death Knight, Paladin and Warrior wear. With Strength or Intellect, Conqueror's Aegis Legplates suits Arms, Fury and Protection Warrior; Holy, Protection and Retribution Paladin; Blood, Frost and Unholy Death Knight.
Transmog Sets
Conqueror's Aegis Legplates is part of the transmog set Conqueror's Aegis Plate (Paladin only). The other 16 pieces:
Items Numbered Next to Conqueror's Aegis Legplates
Blizzard numbers items as they are created, so the named items next to ID 46153 (46148 to 46158) were usually added in the same batch as Conqueror's Aegis Legplates: the same quest line, zone, vendor or reward set.