At the time of the Tarsian War Danar was an idealistic young man who answered his people's call to service by joining the Angosian military. Danar served in many campaigns during the war, and received 2 promotions to the rank of Subhadar.
When faced by defeat due to their primitive technology, Roga and hundreds of other prime soldiers were selected for an enhanced soldier program, which was ordered by Prime Minister Nayrok. In this program soldiers went through intense psychological manipulation and biochemical modifications, and mental "programming" that forced Danar and the other soldiers to become the perfect soldier. The intelligence, memory, strength and reflexes were all enhanced and compelled these soldiers to survive at any cost. When the first of the enhanced soldiers returned from the war victorious, they were unable to control themselves during peacetime - a lost temper could lead to murder.
The Angosian government found they had two choices, which was to rehabilitate the soldiers, or hold them on Lunar V. Put to a vote of the Angosian populace, the second option was chosen. All the soldiers were relocated to Lunar V, a military facility where the enhanced soldiers could be contained in case the government needed to use them again in any conflicts in the future. Though initially it was under their control and most of the soldiers were comfortable, Nayrok had security implemented on the base when Danar and a few others began to resist the Angoisan government.
In 2366, while Angosia III was applying to join the United Federation of Planets, Danar successfully escaped from Lunar V, killing 2 security guards and sabotaging the base's tracking station. This left Lunar V in a state of chaos while Danar got away in a transport ship. Without adequately trained pilots to pursue him, Nayrok asked the visiting USS Enterprise-D to detain him, claiming he was a "dangerous criminal". Although Roga was initially successful by using several different methods of hiding and deception from the ship's sensors (from which he learned during his time in the army). He ultimately was brought on board and overpowered by Commander William Riker and Lieutenant Worf (but not before injuring crewmembers Sonya Gomez, Kieran Duffy, Gar Costa, Cliff Meyers, and Koji Oliver). (TNG episode: "The Hunted"; SCE eBook: Many Splendors)
While in custody in the Enterprise-D's brig, Counselor Deanna Troi sensed something disturbing; although Roga was incredibly dangerous when threatened, he was calm, remorseful about his time in the war, and terrified of returning to Lunar V, when he was at peace. She reported her suspicions to Captain Jean-Luc Picard, and stated that inherently that he had a non-violent personality. Picard at first was unwilling to intervene on Danar's behalf. Troi then approached Data to search Angosian computer records to find out more about Danar's background, and then learned that Danar was a soldier.
This led Troi and the rest of the senior staff to discover the truth about the Angosian's enhanced soldier program. Doctor Crusher reported that Danar's physiology had been significantly altered, and Troi reported that he had been subjected to intensive psychological conditioning. She also reported that Danar had not committed any crimes and had been ordered to report to Lunar V. Despite what they learned, Captain Picard was legally obliged to return Roga to the arriving Angosian security personnel. (TNG episode: "The Hunted")
When the Enterprise crew tried to beam Danar on to an Angosian police shuttle, Roga was able to break free of the transporter beam - a feat that Picard had never seen anyone accomplish before. (TNG novel: Q-Strike) Roga led Enterprise security on a chase throughout the ship. Planting a phaser set to overload next to the external sensor controls, he then headed for a cargo bay. When the phaser exploded, it took out the external sensors. After a brief struggle with Worf, Danar beamed himself on to the police vessel, but instead of the holding cell as originally intended, he beamed himself into the pilot compartment, and hijacked the vessel. (TNG episode: "The Hunted")
Now free, Roga attacked Lunar V, allowing hundreds of fellow enhanced soldiers to rebel and overpower the guards. Twelve of them joined with Roga and went back to Angosia III, where they held Nayrok and the other ministers hostage and demanded to let them come home. Picard convinced Nayrok to allow Roga and his fellow soldiers return home. The Federation gave assistance in helping to rehabilitate the soldiers, who were given treatments for the alterations they received when they went into the original soldier program. Though Roga retained his physical and mental enhancements, he gained a partial-relief from his mental instabilities, giving much peace of mind. (TNG episode: "The Hunted")
In 2374, during the Dominion War, Roga was recruited by Section 31 to prevent the Dominion from seizing control of the Guardian of Forever on Planet Gateway. After completing his mission successfully, Roga asked the Guardian what it desired. When it said it wanted freedom, Roga granted it permission to leave Gateway, which it did. (DS9 - Strange New Worlds 9 short story: "Orphans")