The Firstborn are here my freind.

IG Regiment Overview

Regiment Name: Vostroyan Firstborn
Homeworld: Vostroya
Specialties: Urban and winter warfare

Vostroya is a world in the Halo Zone beyond the Eye of Terror, which swore allegiance to Mars during the Age of Strife. It is now ruled by a committee of Techtriarchs, a mix of Mechanicus Magos and more traditional Imperial planetary government. During the Horus Heresy, Vostroya refused to provide regiments to the Emperor, preferring instead to reserve the population in the manufactorium blanketing the world. After the Heresy came to an end the Vostroyans agreed to supply every first born son to service with the Imperial Guard.

Recruitment & Training

Vostroyan soldier,According to Vostroya's Offering of the First Born, the eldest son of every family must enlist in the Regiments. There are no exceptions to this law, which applies even to the Techtriarchs and the most noble families. For most Vostroyans, it is an honour to join the Firstborn, as great importance is attached to the payment of the debt owed to the Emperor millennia ago.

Unlike other Imperial Guard regiments that are raised en-masse, the Firstborn get a steady flow of new recruits from their homeworld. As a result, the Firstborn regiments have existed unbroken since they were first created. This is not always easy to organize, but ensures that Vostroyan regiments maintain their highest potential, as well as ensuring there's a core of veteran warriors. One consequence of this method is that the Firstborn are considered a brotherhood of warriors and are proud to train the recruits according to their own exacting standards. Few Imperial Guard regiments have a stronger brotherly bond than the Vostroyans.