Mortarches are the elite servitors of Nagash who direct the Undead Legion at his direct behest. With the coming of The End Times, they have gathered to assist Nagash in his goal of the death and reanimation of all life on the world. Formed in emulation of the nine nobles who served as Nagash's lieutenants (and likely inspired by Sauron's nine Nagzul at the meta level) in Khemri back when he was human, each is a powerful and elite undead warrior, several of whom ride a unique Dread Abyssal. One Mortarch, Arkhan, is also the only remaining member of Nagash's original nine from Khemri. While Nagash appointed nine Mortarches, only five were playable during The End Times (Dieter used to be playable, back in 4th Edition Warhammer fantasy, but last anyone heard of him he stuck in the Underworld after being turned into a Cerberus expy. Walach was playable in 5th edition and Luthor had his profile and army during the 6th edition, but he wasn't playable in official tournaments).
By End Times: Archaon, several of them turned on Nagash; the Nameless jumped ship to Chaos for kicks, Mannfred was always eager to turn on Nagash and first did so after Nagash gave him to the Incarnates for Aliathra's death and Walach turned to Khorne and got killed by Vlad for it. Apart from that, Vlad only served Nagash to get Isabella back, Neferata only serves because of Nagash's power over her, Arkhan's loyalty doesn't stop him from privately criticizing Nagash at times and Luthor Harkon's mental instability meant his loyalty was questionable despite following Nagash's orders until a possessed Isabella killed him.
The only unquestioningly and unreservedly loyal Mortarches were Dieter and Krell; Dieter got demoted as mentioned above and Krell was killed three times with Nagash not bothering to bring him back after the third death, the first death being decapitation by a Tomb Scorpion, the second being swallowed whole by a Greater Daemon of Nurgle and the third being beaten to death by Slaanesh's champion Sigvald for ruining his pretty face during a challenge.
List of MortarchesEdit
Age of SigmarEdit
To manage his new realm of Death and collect all the souls that he imagines he's owed, Nagash reestablished the Mortarchs. Every Mortarch that got a new model during the end times reprized their roles, including Mannfred using the Starscream approach of super apologizing (also because Mannfred's schemes act as a goad for the other Mortarchs, a reminder for Nagash not to get complacent and whenever Mannfred fails Nagash enjoys torturing him over it).
After establishing three of the originals, Nagash sought out more Mortarches to lead his various factions. Ushoran also made it to the new setting, but he proved too elusive and mentally unstable to be put to the task of uniting the also unstable Flesh Eater Courts under one banner. When the Nighthaunts emerged en-masse following the Necroquake, Nagash found that Lady Olynder had organized many of them into an Empire. He appointed her Mortarch of Grief, her name based on the waves of sorrow radiating from her that drew Nighthaunts and could be weaponized against the living, later marrying her to Kurdoss who served as her adviser to help curb her tendency for recklessness. During the Soul Wars Olynder killed the Celstant-Prime and freed Katakros' soul from one of Sigmar's Stormvaults, then Nagash gave Katakros a new body and to work building up Nagash's new Stormcast-inspired army the Ossiarch Bonereapers (build up literally, as their bodies are made from souls put into new bodies of re-molded bone and Katakros is in charge of collecting a "Tithe of Bones" to keep making more).