The Maledictors Chapter was formed as part of the 22nd Founding of the Adeptus Astartes in the 36th Millennium. Regarded by many scholars as one of the most successful formations of chapters, the 22nd Founding came at a time of great upheaval in the Imperium. The Age of Apostasy had officially ended with the death of Vandire, while the newly formed Adeptus Sororitas were beginning to spread the reforming principles of Sebastian Thor. The shadowy new division of the Inquisition, the Ordo Hereticus, began to purge those it saw as corrupting the Imperium. For the Genitors on Mars the 22nd Founding was a chance to correct the numerous problems that had beset the previous, so-called "Cursed Founding". With the implementation of new screening techniques for geneseed and stringent security measures, they sought to produce chapters of reliable and steadfast warriors.

The Maledictors came to be located in Anargo due to several factors. As the Age of Apostasy ended, the Anargo Sector remained engulfed in a bitter civil dispute between the pro-Vandire capital and the Thorian Subsectors of Meksum and Archaios. Several neighbouring sectors also suffered a similar predicament. The Adeptus Terra called for a chapter to be located in this unstable region; however, the process of establishing a geneseed line and creating the marines was slowed by numerous disputes between the Priesthoods of Mars and Terra. Adeptus Terra was forced to speed up its deliberations when the massive Waaagh! Tuskragga ripped into the Cruciatine Sector and threatened to destabilise the entire region.

It was not long before an offshoot had turned towards Anargo and laid waste to the fertile worlds of the Massilian Subsector. A fierce and bitter war raged for some fourteen years involving Imperial Guard Regiment from across the Sector. At this vulnerable time, the Alpha Legion used the confusion to sow the seeds of revolt on many worlds, crippling supply lines and causing widespread disturbance. As the still divided Sector reeled from the onslaught within and without, it seemed to many that the all of Anargo may crumble. It was mainly thanks to the Silver Skulls chapter that the Imperium was able to wrestle control of many worlds from the Orks and take steps to restoring order. 40 years later the Gaian revolt on Anargo saw the reunification of the Sector and the beginnings of reconstruction in the Massilian Subsector. It was at this point that the High Lords finally reached a consensus on plans to establish an Astartes Chapter present in the region.

In 649.M36, the Maledictors Chapter was formally founded and they received their Chapter Symbol and their livery. They are given a decree to patrol the region of space including Anargo and the neighbouring Sectors. Soon the first marines, under guidance from officers of the Silver Skulls, began participating in battles across the Anargo Sector. Many challenges faced the Maledictors as they began to gather resources, ships and to secure the rights to recruit from new worlds. Faced with a burgeoning Ork Empire on one front and a hidden enemy all around them battlegrounds were easy to come by. These early encounters helped forge the Maledictors hatred and loathing of the Foes of Mankind.

A Thousand Curses
The noise was soft, it drifted like a wisp, a shadowy echo of sound through the empty halls and cloisters of the Maledictors battle barge. Barely audible over the ever-present hum of the ancient vessel the sibilant whispers wind around the carved arches of the ship in coils of bitter scorn. It was the gentle soothing lullaby that preceded the chapters march to war, the inscribing of the curse litany, their call to battle. Not for the Maledictors are the raucous celebrations or pious contemplations of other chapters, instead, in silence they carve their curses to the enemy upon sheets of lead, their promises of doom for the enemies of the Emperor.