Bulwark of Kings

The Bulwark of Kings is the upgraded epic level breastplate that is craftable and wearable only by blacksmiths with the Armorsmithing specialty.

Source
This item is crafted by blacksmiths with a skill level of 375 who also have the Armorsmith specialty. The components are:

The plans can be learned from the Armorsmith trainers:
 * Grumnus Steelshaper in Ironforge
 * Okothos Ironrager in Orgrimmar
 * Zula Slagfury in Shattrath City