Adeptus Immateria Cartographum

The Cartographum is a section Adeptus of the Adeptus Terra composed of many of the greatest Navigators in the Imperium: they have the mission to explore and map new routes of travel through the Warp and Real Space. Traveling for years at a time in small, lightly-armed vessels, they must use trickery and guile to survive in the harsh 41st Millennium.

Origins of the Adeptus
In early M36, in the midst of the Age of Apostasy, warp storm instances increased and warp travel became impossible between most planets. In the midst of the time of chaos, a small group of Administratum Adepts met in secret and vowed to form the Adeptus, to recruit the very finest Navigators and re-map and re-forge the Imperium.

Though the Imperium was decaying and corrupt, they were men and women of integrity, who feared both for the Imperium and for their lives: Goge Vandire was insane, and they hoped that with this new Adeptus they would be able both to help stabilize the Imperium, and to escape from Terra and get beyond the bloodthirsty reach of Goge Vandire.

It is said that Vandire had a huge map of the galaxy plotting the up to date warp storm movements so that whenever a new planet was revealed, he could send out a fleet to reinstate his will; it was the Adeptus Cartographum that contributed most to this infamous map, their exploring work twisted into a tool of bloody conquest.

Conspiracy against Vandire
The Adeptus was involved in several conspiracies against Goge Vandire, none of which came to fruition, and also had a part in spreading the word of Sebastion Thor, helping to rally the people of the Imperium against Vandire.

After Vandire
After the death of Goge Vandire and the ascension of Sebastion Thor, the Adeptus was officially consecrated as an Adeptus of the Adeptus Terra, independent of the Administratum, with the mandate to map Warp routes, explore lost systems, and take a part in the re-unification of the Imperium after the Age of Apostasy.

Current Organization
The Adeptus has remained organizationally unchanged since the fall of Goge Vandire: They maintain a small base on Terra attached to the Adeptus Astronomica, along with a few minor bases at strategic points.

The Adeptus is commanded by the Master Navigator, who oversees the revruitment and training of Navigators from all over the Imperium.

Along with the Master Navigator, the Adeptus has a number of other officers such as the Shipping Chief, who coordinates the movement of the Adeptus's ships; the Storm Caller, who plots the passge of Warp Storms and other phenomena.

Ships
The Adeptus Cartographum maintains a fleet of over a thousand ships, scattered across the Imperium. Small, fast, and lightly-armed, they can usually run away form trouble, when it occurs.

Marriage and Navigator Families
The unique powers of the Navigators are passed down through each generation. The navigator gene itself can only be preserved by intermarriage - it is lost when a Navigator breeds with an ordinary human. This has led to the development of the closely-related, often inbred, Navigator families.

The Navigators of the Adeptus Cartographum are recruited from practically every Navigator Family in the Imperium: spending years, often decades at a time without contact with their families, peculiar friendships and romances have grown within the Adeptus; scions of bitter enemies have become comrades and even lovers; several new Navigator families have been born from the Adeptus.