The Aldara was a Cardassian Galor-class warship under Gul Danar that chased the Bajoran fugitive Tahna Los to Deep Space Nine in 2369 and demanded that he be handed over.
The Aldara appears in the Deep Space Nine episode Past Prologue. It is first seen firing on a small Bajoran scout ship as it flees towards the station, whose pilot, Tahna Los, asks for asylum as he is beamed aboard.
Gul Danar tells Commander Sisko that Tahna is a member of the Kohn-Ma, a splinter group still attacking Cardassians after the end of the occupation, and insists on his return. Sisko refuses to give him up until the request for asylum has been considered, and the Aldara remains nearby.
Later, when Tahna tries to use a bilitrium bomb to seal the wormhole, the Cardassians are waiting at the border, and Tahna is forced to surrender to Sisko rather than fall into their hands.