Madred

Madred was a Cardassian male living in the 24th century. He held the rank of Gul and served in the Cardassian Guard's Military Intelligence branch, where he had a reputation as a skilled interrogator. 

In the late 2340s, Madred held the rank of Glinn, and was stationed on Kora II; he encountered Elias Vaughn and several other Starfleet Intelligence operatives there in 2347. ( : )

In 2369, he interrogated Federation Captain Jean-Luc Picard on Celtris III. His failure to break the human remained the one black spot on his record. ( : )

In the aftermath of the Dominion War, Madred sought political power on Cardassia Prime, hoping to rebuild the Cardassian Union to its former glory. He approached Elim Garak for his support, but Garak refused, and instead gave his allegiance to Alon Ghemor's democratic government. ( s: ', ')