Macet responded to the attack of a Cardassian outpost by the USS Phoenix in 2367. He found the outpost incinerated, and determined the attacker be a Starfleet ship, but lost track of it. He used the event as an excuse to attack the USS Enterprise-D which was near their border at the time. He claimed they were at war, now, due to the attack on an unarmed science station. In reality, it was a military facility. However, his ship proved no match for the Galaxy-class Enterprise-D, and he agreed to a truce after his ship was disabled.
Due to a high-level diplomatic exchange, Macet was brought on board the Enterprise-D as an observer along with Glinns Daro and Telle as it tracked down the Phoenix. Captain Jean-Luc Picard brought him in on the information, seeing that the Phoenix was believed to have gone rogue under orders from Captain Benjamin Maxwell. Macet immediately believed that Maxwell was seeking revenge for the death of his family in the Setlik III massacre. He asked that Cardassian ships be given an advantage to disable the Phoenix before it destroyed more of their people. Picard relented, but the ship continued its rampage.
In the interests of peaceful cooperation following the recently signed treaty ending the Federation-Cardassian War, Macet punished Telle when the latter was caught attempting to access secured systems aboard the Enterprise-D. Picard didn't press the issue, which seemed to please him. Macet said he was not a man who wanted war, and thought Picard wasn't, either.
Ultimately, the Phoenix was located and returned to Federation space. However, Picard relayed Maxwell's allegations of a renewed Cardassian buildup to Macet, warning him, "we'll be watching." (TNG: "The Wounded")
Macet was the first Cardassian seen in the Star Trek saga and the only Cardassian to ever appear with facial hair. His onscreen reveal was described in the episode's script as "A Cardassian Gul (Captain) appears. These are humanoid aliens -- sleek, handsome, intense."
Macet appeared in several of the Deep Space Nine relaunch series novels, including the Gateways Deep Space Nine entry Demons of Air and Darkness, Unity, and the Worlds of Star Trek: Deep Space Nine novella The Lotus Flower. The similarities between Macet and Dukat were explained as being due to the fact that they were cousins. However, Macet was a much more honorable man than Dukat. The Pocket DS9 story Fearful Symmetry implies that he grew facial hair as a conscious effort to lessen this resemblance. Macet joined Damar's Cardassian Rebellion and fought against the Dominion – in Demons of Air and Darkness, it was established that he commanded the fleet which attacked Rondac III in "The Changing Face of Evil".
In the Star Trek: Deep Space Nine - Mission Gamma novels, his first name was established as Akellen.
His mirror universe counterpart (β) appears in the novel Warpath and the short story "Family Matters" contained in the anthology Shards and Shadows. He was the commanding officer of the Klingon-Cardassian Alliance vessel Trager during the 2370s.