Cardassians were a humanoid species from the Alpha Quadrant. They were native to the planet Cardassia Prime, capital world of the Cardassian Union. Known throughout the Alpha Quadrant for their ruthlessness, the Cardassians became one of the greatest enemies of the Federation and Klingon Empire when they joined the Dominion in 2373. Their xenophobic attitude towards other species was well established throughout the quadrant after the Setlik III massacre during the Cardassian Wars, as well as when their atrocities from the Occupation of Bajor were revealed after their withdrawal in 2369.
In its ancient history, before Cardassia became a military dictatorship, the Cardassian society was known as the Hebitians. It was home to fine art and beautiful architecture. Once the Hebitian civilization fell into decay from lack of natural resources, millions of Cardassians were starving and the planet was subjected to utter anarchy. Though the Hebitian society and way of life eventually became extinct, the remaining Cardassians turned to the military to solve their problems. This began the Cardassian policy of expansion into the galaxy, to provide the much-needed natural resources to sustain its population.