Tret Akleen
According to a scene cut from the final version of the  sixth season episode , Tret Akleen was the father of the Cardassian Empire. 

Akleen was born on the second planet in the Ventani system, which was therefore considered sacred ground by Cardassians everywhere. Elim Garak suggested that the Federation Alliance attack that system (instead of the Chin'toka system as was later decided), to give the Federation a propaganda victory over the Cardassians because the loss of Akleen's birthplace would be felt as devastating to them. Worf noted the Ventani system held no strategic value and Benjamin Sisko commented that the loss would have no effect on the Jem'Hadar. (Star Trek: Deep Space Nine Companion - A Series Guide and Script Library)

In A Stitch in Time, Andrew Robinson describes Akleen as being: "The putative founder of modern Cardassia."

External link

Akleen, Tret