Legate Matan was a Cardassian living in the 24th century. He was the head of House Arterius and worked to return the Cardassian Union to its status as a superpower by launching a series of attacks of Federation, Klingon, and Romulan forces.
In 2378, Matan commanded a large fleet in the Maelstrom. He first encountered the USS Sovereign and IKS JonKa at the Belaruz system, telling them to leave their territory. When they refused, Matan attacked the JonKa, and a battle ensued. After losing some ships, Matan retreated.
In order to strengthen his forces, Matan sought allies. To this end, he approached the Kessok, warning them of the Federation and their expansionist nature. Through his fear mongering, the Kessok government gladly gave Matan both their ships and their technology. He met with a Kessok ambassador at Napenthe when Sek, a gul under his command, discovered the Sovereign spying on the proceedings. Matan fled, leaving his forces to fight back Starfleet.
Utilizing the technology the Kessok shared, Matan developed powerful Hybrid-class vessels and began a large scale assault on Federation, Klingon, and Romulan ships throughout the area, as well as bases and colonies. In addition to his powerful fleet, Matan made use of Kessok solarformers to destroy stars. It was revealed that such a solarfomer was responsible for destroying the Vesuvi star earlier.
His war came to a head at the Omega Draconis system, where he joined the battle in his flagship- a Keldon-class vessel outfitted with a Romulan cloaking device. He then threatened to use the solarformer at Omega Draconis to detonate that star, unconcerned about the new Kessok colony in the system. His fleet decimated and having betrayed his allies, Matan decided to attack the solarformer in a last ditch effort to destroy the enemy fleet. Before he could carry out his plan, his ship was disabled by the Sovereign, and as the war ends, he drifted into the star and perished. (TNG video game: Bridge Commander)