The Van Diemen system's primary star is a Yellow-white F4 furnace of a star somewhat brighter than Sol. It is circled by six planets, but only one of them is significantly inhabited. This is Van Diemen III, usually simply called Van Diemen, a world slightly larger and heavier than Earth, but farther out from its star. Its thick atmosphere and bright star make it a very hot world, but its significant axial tilt means that the poles are rather cool except in the high summer season of each hemipshere. The equatorial and temperate latitudes are covered with boiling-hot seas or scorching-hot deserts, where only small mining settlements and a few solar-power stations break up the vast wilderness.
Most human settlements are clustered near the poles, with the city of Darwin in the North Polar Region serving as the "summer capital". Many inhabitants of the polar cities commute to the opposite pole twice a year, to spend each hemispheric summer in near-permanent daylight and pleasantly warm weather. Some less savory elements make the opposite commute, to take advantage of the 8 earth months of near-permanent darkness each hemispheric winter and the cheap prices in the less crowded cities. When the planetary government leaves Darwin each winter, they spend the southern-hemisphere summer in the "Winter capital" of Huxley. Altogether, there are nearly a billion inhabitants in the Van Diemen system.
Originally catalogued as the D8 system, Van Diemen was colonized almost simultaneously by both the Humans and the Drakat, with the Drakat on the southern polar region and the humans in the north. Disputes over this strategically-located system led in 2146 to the D8 Crisis, which led to war with the Drakat two years later when the Drakat cruiser Tregak crash-dived into the main human settlement of Darwin. With their defenses wrecked and Earth Fleet in poor shape after a prolonged period of peace with the Bugs, the Federation was forced to abandon D8 and withdraw to New Paris. After a hastily expanded Earth Fleet narrowly defeated the Drakat armada in the Battle of New Paris, a Tech Infantry counter-attack landed on D8 in 2153, under the command of Admiral Rebecca Blacklidge. Although the assault was successful, Van Diemen III's harsh landscape and large wilderness areas led to a prolonged guerilla war with stranded Drakat troops and colonists. D8 as renamed the Van Diemen system after the great Mage general Cathar Van Diemen, a Tech Infantry legend of the early Bug Wars who fell to a Drakat assassin during the mopping-up phases of the conquest of this system. After alliance with the Katarn finally allowed the Federation to defeat the Drakat, colonization efforts began in earnest in the 2160's. Later, Van Diemen saw some of the heaviest fighting of the last days of the Third Civil War, when General Joel Fabin was forced to make his last stand here after being forced off of Wilke's Star.