Maquis

The Maquis was a group formed by former Federation citizen in the Demilitarized Zone who banded together to defend their homes from the Cardassian aggression.

History
The Maquis announced their existence with the bombing of a freighter that was supplying the Cardassian colonists of the DMZ with weapons followed this by kidnapping Gul Dukat. 

Following the Klingon Empire's invasion of Cardassia the Maquis were emboldened and made significant gains against the severely weakened Cardassians. During this time the Klingons gave aid to the Maquis, including cloaking technology. 

The Maquis gains were reversed when the Union joined the Dominion in mid-2373. The Jem'Hadar swept through the DMZ and managed to do in a few days what the Cardassians failed to do in three years and wiped out the Maquis. 

Alternate realities
In an alternate reality, after the Cardassian Union fell to the Klingon Empire the Maquis found themselves in conflict with the Klingons after they invaded the DMZ. 

People

 * List of Maquis