There were a series of books (I think there were 5 when I started reading them) primarily set around a captain whose ship is destroyed at the beginning of a war and escapes in a evacuation pod. He is put into cryosleep and his escape pod is damaged during his escape so his pod is never recovered. Fast forward 100 years (I think, can't exactly remember), the war is still waging and his pod is finally picked up by a friendly (luckily!) fleet.
Following the execution of the current commander of the fleet he is instantly promoted to commander. The fleet is deep behind enemies lines and due to decades of fighting, strict military regulations have degraded. Because of his understanding and expertise with advanced tactics and the loss of such tactics by combatants of the war, he and the fleet are able to carve a path back home.
I never actually finished the series and can't find any of the books anywhere (and obviously can't remember what they're called). I thinks its a fairly new series, perhaps from around the turn of the century, maybe later.