Lin was a member of the Bajoran resistance. When the Cardassians evacuated Bajor, he found there was a gaping whole in his life. All he’d known was fighting Cardassians; now they were no longer the enemy. He joined the militia but it wasn’t enough.
He left Bajor and joined the Maquis in order to go back to fighting Cardassians. There he fought with distinction under the likes of Michael Eddington and Thomas Riker. When the Dominion moved decisively against the Maquis in 2373, he was away on a mission. Thus he survived the final series of confrontations and the wholesale slaughter that occurred on places like Athos IV.
With the Maquis no longer a viable option, Lin went cap in hand to Starfleet. He freely admitted his past, believing that it would catch up to him sooner rather than later so better to have it out in the open.
Needless to say, Starfleet did not trust a former Maquis but they were desperate for experienced soldiers. Lin was sent on routine missions but soon proved himself not only capable but worthy of trust. He slowly moved up through the ranks, finishing the war as a sergeant.
After the war, he enrolled in Starfleet Academy. It was an unusual move for someone who had always been a foot soldier but Lin wanted more than the slog of ground forces. He’d been there and done that and was looking for something new in his life.
Nonetheless, the Marine Corps is still in his blood. He might well be one of the few Starfleet commanders who actually likes marines. That is partly why he was offered the position on Deep Space 14. If the Romulans decide to turn nasty, it might well be the Marines who are dispatched to sort it out. With Marines being part of the construction team on the station, Starfleet decided that an officer who can work with them might be the ideal choice for the position of Executive Officer.
A posting to Ch’Areinnye also gets him well away from the Cardassian Union and might allow him to view his situation dispassionately, rather than through a cloud of prejudice and hatred.
Lin is thin, so much so that he could be described as gaunt. It is a product of a hard life with few nutrients at vital stages of his physical growth. Much as he tries to put his past behind him, Lin is driven by hatred of Cardassia and all things Cardassian. As far as he's concerned, the Jem'hadar raid on Cardassian was a failure because some Cardassians survived. If it was up to him, Cardassia would be left isolated and spurned; its people dying of starvation and disease brought on by their own actions. Spouse: Arnys (deceased). Children: None. Father: Baril. Mother: Manell Drin. Brothers: Ranik (deceased - older). Pariel (younger). Sisters: None. Other Family: Lin does not speak about 'other family'. Some died in the Occupation, some were collaborators. The latter are dead to him.