A Cerastus Knight-Lancer is one of the more uncommon patterns of Imperial Knight-class armoured walkers, but also the most highly valued pattern fielded by the Knight Houses. The Cerastus Knight-Lancer is a first strike weapon, attuned to rapid assault tactics and lethal outflanking charges against a foe. It is justly renowned for its speed and its power, as well as for the temperamental and restive nature of the machine-spirits which dwell as anima within its colossal frame. Because of this reputation, the most impetuous and glory-hungry scions of the Knight Households are driven to bond with these war machines, their own souls a match for the fury caged within their mounts. The greatest of these pairings will go on to create martial legends among their lineage, while for those whose temper cannot fully master that of their Knight-engine or whose own lust for glory might see valour outweigh caution on the battlefield, their triumphs are likely to blaze brightly, if briefly, in the chronicles of their Households.
The Lancer is the most widely known variant of the Cerastus type Knight armour, a highly sophisticated chassis whose speed and agility far exceed the clumsier Errant and Paladin types. The Cerastus type Knights appear to have been designed solely for war; not as protectors like traditional Knights, but as blood-handed conquerors and tools of destruction that would leave a legacy of the violence that marked the beginning of Age of Strife. The Cerastus Knight-Lancer is held in high esteem by the more impetuous of a House's scions, its potent Ion Gauntlet Shield and Shock Lance perfectly suited to battling the foe face to face, where only a perfectly timed thrust of the lance stands between a scion and death. In particular, those scions who follow the Uhlan traditions favour the speed and ferocity of the Lancer, and when rival Knight Houses meet in combat, these warriors race ahead of the Household to clash in single combat with the enemy's champions.
The history of the Cerastus Knight-Lancer as presented above is canon culled from Codex: Imperial Knights for the 7th Edition of the game. The original incarnation of the Knight Lancer was provided in the supplement found in White Dwarf 126 (UK). This account of the Knight Lancer's history differed greatly from that given above and has largely been superseded by the newer canon, however, it has been included in the article and is also presented below. Please note that the below contains old information that is no longer considered canon according to the current iteration of the Warhammer 40,000 universe:
The Knight Lancer is a variant of the standard Knight suit that has been designed for speed and agility. The Knight Lancer is most usually used to perform scouting actions, outflank enemy forces and distract them while heavier units can position themselves to attack. The Knight Lancer is equipped with a Battle Cannon to give it long range fighting capability, but its true armament is the Power Lance. The Power Lance is a relatively simple upgrade to the standard Shock Lance that is mounted on other Knight patterns. It operates by intensifying the bolt of energy normally expelled from Shock Lances, changing it into a searing arc of lightning capable of rending all but the strongest of armour plating and causing havoc in enemy ranks. The Power Lance has a very short range, but its nature makes it the perfect weapon for hit-and-run attacks.
- The Horus Heresy - Book Three: Extermination by Alan Bligh, pg. 231
- The Horus Heresy - Book Four: Conquest by Alan Bligh, pp. 26, 41, 60-62, 75, 99, 112-113, 116-117, 120-121, 128-129, 132-133, 136-137, 194, 213, 295, 305
- White Dwarf #126 (UK), "Space Marine - Knights," by Andy Chambers, pp. 31, 38, 42-43, 45
- Forge World - Cerastus Knight-Lancer