Armed with handcrafted weapons passed down through the generations, the Vostroyan Firstborn hail from the Industrial Hive World of Vostroya. To atone for a sin committed during the Horus Heresy, every Vostroyan family must pledge their firstborn son to serve in the Imperial Guard. It is common for family ties to exist in Vostroyan regiments; it is typical for cousins to serve together, and for new recruits to be mentored by their older battle hardened relatives.