The Cardassian Union ws formed in Earth year 1871 under the civilian Detapa Council, which controlled the Central Command (military) and the Obsidian Order (internal security and intelligence). Before the military took over the government, starvation, and disease ran rampant on the resource-depleted homworld. Architectural and agricultural renewal came with the violent process of expansion and warfare.
The Cardassians first offered assistance to Bajor in 2309 and annexed the planet in 2328, and those Bajorans who didn't resettle were tortured or forced into hard labor. Tiring of the constant Bajoran rebel terrorist activity, Cardassia withdrew from Bajor in 2369 and abandoned the mining station Terok Nor orbiting the planet. The withdrawal was mistimed, however; shortly thereafter, the Bajoran wormhole was discovered near the planet, and the station, redubbed Deep Space Nine by the Federation, became strategically vital to the quadrant. The Cardassians are now eager to regain control of the station by any means possible.
After 20 years of conflict, the Federation signed a peace treaty with Cardassia in 2367, although the Cardassians continued covert arms build-ups and military preparations. Shortly after Cardassia signed a peace treaty with Bajor in 2371, the Obsidian order made a disastrous attempt at a first strike against the home planet of the Founders, leaders of the Dominion. Afterward, military control of Cardassia was overthrown and power shifted to the civilian government. The Klingons then attacked the homeworld and were defeated, but many worlds in the Union were defeated. Recently, Cardassia became part of the Dominion, with Gul Dukat as leader of the planet.