Altaria has the strategic fortune of being located in the outer rim. As a result, even its handful of colonies are relatively unimportant from a strategic standpoint. The Drengin Empire had largely ignored the Altarians during the Dread Lord war of 2225. But the Dread Lords tended to put specific effort to do harm to the Altarians.
According to Altarian legend, the Dread Lords were involved on Altaria during the opening stages of the Precursor wars eons ago. The war between the Precursors (the Arnor and the Dread Lords) nearly wiped out Altaria. This time period is still known as the cataclysm in which the surface of Altaria was decimated and over time, the world was recolonized bit by bit.
In the infamous "Altaria Resists" incident, the Dread Lords with Korath support were driving towards the Altarian home world in an effort to eradicate the Altarians. It is quite unlike most of the epic battles as the space it occurs in was immensely large while having relatively few planets to fight over. It was this literal distance that served as the only hope for the Altarians in keeping the Dread Lords at bay.