Marius Gage's origins lie at the closing years of the Unification Wars on Terra. He was a part of the nascent XIIIth Legion's "Alpha" intake -- the test bed raising of several thousand warriors by which its gene-seed's stability and adaptability was judged -- was passed firmly within acceptable parameters. Soon, the XIIIth Legion, known as the "the War-born" to those whom they served alongside, quickly proved their worth. The XIIIth Legion took part in the earliest phases of the Great Crusade, including the liberation of the Segmentum Solar. During this period the XIIIth, then around 8,000 strong, began to make its mark by taking part alongside other Legions under the Emperor's direct generalship, gaining renown in notable campaigns such as the Liberation of Diurnus and the destruction of