Which TNG episode introduced the Cardassians?

“The Wounded” introduced the Cardassians to Star Trek: The Next Generation. The fourth-season episode first aired in January 1991 and established the Cardassian Union as a former enemy of the Federation that had recently signed a peace treaty.

The story follows Captain Benjamin Maxwell of the USS Phoenix, who attacks Cardassian targets because he believes they are secretly preparing for another war. Captain Jean-Luc Picard and the Enterprise-D are sent to stop him, while Cardassian Gul Macet assists with the investigation.

The episode is also notable because Marc Alaimo played Macet before becoming best known as Gul Dukat on Star Trek: Deep Space Nine. Although the Cardassians later became central to DS9, “The Wounded” is their canonical debut in TNG. A common mix-up is confusing their introduction with “Chain of Command,” which expanded their history and referenced their withdrawal from Bajor.