...the expansion is set in Northrend and youÂ’ll be fighting the Lich King, it makes sense to add a class that is directly connected to the coming conflict. The death knights you will be able to play are no longer allied with the Lich King; instead, they have joined forces with the Horde or the Alliance to fight against Arthas. So by playing a death knight, youÂ’re engaged in the story of Wrath of the Lich King right from the start, which makes the death knight a logical class choice for the expansion from a lore point of view.

Years after the destruction of Draenor, the immensely powerful Lich King created a new breed of death knights: malevolent, rune-wielding warriors of the Scourge. The first and greatest of these was Prince Arthas Menethil, once a mighty paladin of the Silver Hand, who sacrificed his soul to claim the runeblade Frostmourne in a desperate bid to save his people... In the years since Arthas shattered the Frozen Throne and merged with the Lich King, the power and fury of the death knights has only grown. Now these unrelenting crusaders of the damned eagerly await the Lich King's command to unleash their fury on Azeroth once again.