The Occupation of Bajor, usually referred to simply as the Occupation, was a period from about 2319 to 2369 during which Bajor was under the control of the Cardassian Union. During the Occupation, the Cardassians perpetrated a coordinated scheme of strip-mining, forced labor, and genocide across the planet. Their brutality led to the deaths of more than ten million Bajorans. This eventually gave rise to the fierce Bajoran Resistance, which used guerrilla and terror tactics. The Cardassians eventually withdrew due to political pressure from the United Federation of Planets, as well as the Resistance's constant attacks.
Prior to the Occupation, the Bajorans were a peaceful people whose art and architecture were well-known and admired throughout the galaxy. The Cardassians, by contrast, were a militaristic and often hostile people who had conquered numerous planets in the name of survival. The two peoples nonetheless managed to coexist peacefully for some time; however, the Cardassians coveted Bajor's rich natural resources and saw the Bajoran people as inferior. Cardassia became increasingly hostile as time went on, maintaining a military presence on the planet for ten years before forcibly annexing it in 2328. This travesty caused little galactic outcry, as most major powers were unaware of or unconcerned with Bajor's plight. Even the Federation was unable to interfere, as the Prime Directive forbade it; the occupation was considered an internal matter between Cardassia and a subject race.
Did You Know that Romulan ale was illegal throughout the Federation for at least 100 years before the ban was lifted in 2374, only to be reinstated by 2379, and that despite the embargo, many Starfleetofficers had actually tried the beverage at some time in their career?