Amongst the very first irregular forces raised by the Imperium, and considered the forerunners of the Imperialis Militia, were those of Old Earth who served alongside the Emperor and his Thunder Warrior regiments in the long Terran Unification Wars, or in some cases contested them in battle. When these wars finally ended and the Great Crusade began, the surviving irregulars and militias were integrated into the newly constituted Imperial Army, forming the core of the Imperialis Auxilia, and in time they came to be known as the "Old One Hundred”.

在漫長的統(tǒng)一戰(zhàn)爭當中，那些伴隨帝皇和雷霆戰(zhàn)士們作戰(zhàn)的舊地球凡人軍隊是人類帝國組建的最早一批非正規(guī)部隊，他們被認為是帝國民兵部隊的先驅，而在某些情況下，此類凡人部隊也會與帝皇敵對。等到統(tǒng)一戰(zhàn)爭最終結束，大遠征開始時，這些幸存下來的非正規(guī)軍和民兵被編入新組建的帝國軍，他們成為了帝國輔助軍的核心，從此，他們開始被稱為“老百人隊”。

These much-storied regiments, including the Geno Chiliads, the ConFed Gun Brotherhoods and the Thorosian Vbltigeurs, gained numerous battle honours as the Great Crusade pressed ever outwards, and many of the Old One Hundred were in time granted settlement rights on worlds they had conquered, which would eventually produce a second generation of militia regiments from whose ranks the best would be conscripted into the Imperial Army to fight in the Emperor's ongoing wars. Some regiments however, such as the Lucifer Blacks and the Ouranti Draks, were, for a variety of reasons, judged in some way not deserving of such rights and were tasked with a ceaseless crusade across the stars. These itinerant armies strove to replace their losses by press-ganging from worlds they liberated in an ad hoc manner, transforming over time often into a pale shadow of their former strength. Others, whose service was ultimately indentured rather than given freely, were denied even this mode of recruitment. Such regiments effectively died a slow death of a thousand cuts on a hundred battlefields, and by the time of the Horus Heresy were no more than legends.

這些久負盛名的部隊包括基諾千連團、康非德槍炮兄弟會和索瑞希亞騰躍兵，他們獲得了眾多的戰(zhàn)斗榮譽，而隨著大遠征不斷向外推進，許多老百人隊及時獲得了在他們征服的世界上定居的權力，而這最終將產生第二代民兵團，帝國會從中選拔最好的民兵加入帝國軍來參加帝皇正在進行的戰(zhàn)爭。但是有些團，比如路西法黑衛(wèi)和奧蘭德龍騎兵則由于各種原因被以某種方式判定不應該享有這些權力，他們要在群星間進行不斷的遠征。這些流動的部隊通過從那些他們以特殊方式解放的世界上強征壯丁的方式來努力補充自己的損失。隨著時間的推移，他們往往會變成他們以前力量的蒼白陰影。而其他那些簽訂服役契約而非主動服役的民兵團甚至都不被允許以強征壯丁的方式征召新兵。實際上這些團就是在一百個戰(zhàn)場上遭受了一千次損失，他們在以這種方式慢慢死去，等到荷魯斯叛亂時，他們已經僅僅是傳說了。