Warbringer is a passive warrior talent available at level 15.
Patch changes
Patch 5.2.0 (5-Mar-2013): Warbringer now reduces the target's movement by 50% for 15 seconds (8 seconds in PvP), in addition to its other effects. The 3-second stun/knockdown is now in the diminishing returns category for stuns (same as Shockwave and Storm Bolt), and not the proc stun diminishing returns category.
/Patch 4.0.1 (12-Oct-2010): Moved to tier 3. Minimum of level 29 required to get this talent.
Patch 3.3.2 (2010-01-02): This talent no longer allows Charge and Intercept to break roots or snares. Intervene remains unaffected.