In Wraith: The Oblivion, the Deathlords are the supreme powers of Stygia, each of them the master of one Legion. The Deathlords are subservient to Charon, but without Charon present, they are largely concerned with claiming Stygia for themselves.
The institution of the Deathlords was created at the formation of the Stygian Republic in approximately 200 BC. The authority to divide souls was granted to Charon by his Quest for the Seven Signs from the Shining Ones, and represented a shift from the traditional methods used by the Ferrymen up to this point. Since there were now more wraiths than Ferrymen could handle, Charon began developing the nation of Stygia to process wraiths and lead them to Transcendence. To that end, he recruited wraithly allies to oversee seven different Legions, each classified by their type of death. An eighth Legion, under the auspices of Charon's patron, the Lady of Fate, comprised a semi-independent organization.
The original Deathlords were not Ferrymen; the Ferrymen were generally unimpressed by the concept of Stygia and found the entire project somewhat suspicious. As a result, Deathlords have not undergone the Ritual of Severance and are as prone to Catharsis as any other wraith. In addition, in comparison to the Ferrymen, the Deathlords have always been political creatures. At least two of them were Roman Senators, one was a tribal leader, and the rest seem to have had administrative or leadership roles in life.
The use of the term "seems to" is important because the identities of the Deathlords are unknown. Given the heavy use of masks in Stygian society, the Deathlords can change on a regular basis - and often did when Charon was displeased with them. On at least one occasion, he soulforged a Smiling Lord, and the Emerald Lord from the Great War is almost antipodal in character to the Emerald Lord of the modern era. Likewise, when the Ashen Lady emerged greatly humbled from a major fight with Charon around 500 years ago, many debated if she was the same wraith who entered the Onyx Tower.
The history of Stygian society is one of almost constant increase in the power of the Deathlords as Charon centralized independent organizations under the control of the Legions. After the banishment of the Ferrymen, the Deathlords sent souls willy-nilly to any Far Shore that asked for them. Until the Proclamation of Reason, this practice continued, and since several of these Far Shores were controlled by shadow-eaten, the result was the damnation of uncounted souls due to their ignorance.
The Deathlords, whatever their personalities are, were also pawns that Charon moved around in his complex game with Fate. In the 19th century, unknown to them, he destroyed their Fetters, rendering each Deathlord a domem and strongly limiting their capacity to affect the living world. Charon publicly was in the same boat as them, although he actually fettered himself to the Skinlands as a whole in preparation for his eventual birth and redeath.
At the time of World War I, Charon disappeared for several years, and in a prelude to the breakup at the end of the twentieth century, the Hierarchy fell into civil war. The Smiling Lord took this opportunity to declare himself emperor of the dead, and immediately found himself on the receiving end of the Skeletal Lord's wrath. The conflict continued until the end of the Great War, when Charon returned and with the aid of the Mnemoi ended the insurrection and restored order to Stygia by wiping out all memory of the event.
Each Deathlord reacts in his own way to the Sixth Great Maelstrom, with the Smiling Lord being "administered" to by Nhudri for his crimes, and the Skeletal Lord Harrowed while defending Stygia. The other lords scatter or are destroyed, replaced by those wraiths who reaped Charon and brought him back to Stygia (usually the Player Characters of Ends of Empire).