Prospero

Prospero was the original homeworld of the Thousand Sons Legion of Space Marines and Magnus the Red.

Chosen by settlers for the planets isolated position, although far closer to Terra than many colonies, Prospero had few redeeming qualities - no independent resources, little contact with any outsiders and few sources of nourishment. The only reason for setting a colony there was because it was a very good place to hide, and became such for a large community of psychically talented humans.

During the Great Crusade Prospero had developed into a paradise world. Many of the vast buildings on the planet were massive gold and marble pyramids, although these have only been drawn as such in the CCG game The Horus Heresy. It is depicted as a planet with blue skies and gleaming Egyptianesque architecture. One of the many cities is the capital Tizca, often referred to as the City of Light, where the Thousand Sons held out against the Space Wolves when they were mistakenly declared traitors.

Prospero's 'cleansing' at the hands of the Space Wolves was hastened by the dilapidated state of the planetary defences. As homeworld of a Space Marine Legion, it was standard for the surface of a planet to be dotted by immense defence lasers; sunk into reinforced silos many miles beneath settlements. Orbital fire platforms, automated tracking stations, minefields, as well as a number of the Legion's own starships – All manned continuously and diligently.

The focus of the Thousand Sons, having always been away from the traditional Space Marine role of combat in most forms, led to dangerous weakening of the defence grid. The cavernous subterranean defence lasers were neglected, unmanned and poorly maintained and orbital defences virtually non-existent. As a result, the arrival of the Space Wolves' battle barges went uncontested, their orbit-to-surface ordnance barrages unanswered and their drop-pods unchallenged.

Ironically, whilst the attack was underway, the Thousand Sons focus remained their lore – rushing to save what incalculably precious works they could whilst the righteous, if possibly misplaced retribution of Leman Russ' chapter went unchallenged. Indeed had a defence of Prospero been attempted, more time might have been bought to evacuate the libraries and studies of their ultimately costly work.

The planet eventually became a blasted ruin, picked clean by millennia of looters and rogue traders, declared 'exterminatus' by the Inquisition.