In Wrath of the Lich King it is item level 232, requires level 80 and is named Velen's Pants. In MoP Classic it is item level 245 and requires level 80.
Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Velen's Pants of Triumph Compares
Who It Suits
Cloth is the armor type Mage, Priest and Warlock wear. With Intellect, Velen's Pants of Triumph suits Discipline, Holy and Shadow Priest; Arcane, Fire and Frost Mage; Affliction, Demonology and Destruction Warlock.
Transmog Sets
Velen's Pants of Triumph is part of the transmog set Velen's Regalia (Priest only). The other 16 pieces:
Built from the World of Warcraft client build files and recorded Auction House snapshots.
Where Velen's Pants of Triumph Fits
Other Items Named Velen's Pants of Triumph
1 other item in the current build is also called Velen's Pants of Triumph. Same-name entries are usually a different rank, faction, quest stage or reward track of the same object.
Blizzard numbers items as they are created, so the named items next to ID 48079 (48074 to 48084) were usually added in the same batch as Velen's Pants of Triumph: the same quest line, zone, vendor or reward set.