During the Cardassian Occupation of Bajor, he was a member of the Ornathia resistance cell. He led a raid on Pullock V, a Cardassian planet and the first offworld raid against the Cardassian Union. He had a brother who was freed from the Gallitep labor camp by the Shakaar resistance cell during the Cardassian Occupation of Bajor.
After the end of the Occupation in 2369, Lenaris joined the Bajoran Militia, and rose to the rank of colonel by 2371. That year, his army was dispatched to Dakhur Province to find Shakaar Edon and the rest of his resistance cell, who had defied acting First Minister Winn Adami by not returning several soil reclamators. Lenaris later agreed with Shakaar, that their actions could lead to civil war. He consulted with his fellow army commanders, who agreed to support Shakaar in the election for First Minister. (DS9: "Shakaar")
Lenaris was a colleague of Limis Vircona in the Ornathia resistance cell. The two friends reunited for the first time in fifteen years aboard the USS Lambda Paz in 2375 when that ship was being repaired at Starbase G-6. Lenaris represented Bajor in a joint conference between the United Federation of Planets and Bajor to negotiate personnel exchanges following the latter's dissolution of a non-aggression treaty with the Dominion. ("Faces in the Crowd")