Gul Amark was a Cardassian commanding officer of the Galor-class warship Kenzha.
In the year 2371, along with Gul Dracos of the Serron, he met Benjamin Sisko and the Federation starship USS Defiant at the edge of Cardassian Union space as Sisko was on a mission to attempt to recover Thomas Riker through diplomatic means.
Amark had an interest in the tests that Duran Nol and Sem Veress had been doing on Riker, and informed Doctor Nol that the Federation envoy had arrived and that with Veress' prior findings, the Detapa Council expected that she should be well ahead of schedule. When Amark and Sisko met with the Council, Amark told Sisko that the Cardassians found it suspicious that the Federation wanted Riker back, as if there were a secret to hide. When Sisko insisted otherwise, Amark told the Council that he believed Sisko.
When Sisko left Cardassian space, Amark told him that he was surprised that Sisko had not bartered with the Council after their response, noting that Riker "must not be what we think he is." (DS9 comic: "Sole Asylum")