In Volume 1 time travelers arrive in 1920 to prevent World War 2. They form their own military force and recruit the best from the era. Lothar von Richthofen had a promising career as an officer in the new Terran Fleet, but a mistake caused the Fleet Admiral to suspect his intentions, resulting in exile to another timeline a thousand years in the past.
In Volume 2 Lothar continues his adventures in the 10th Century. As he roams over the ancient world, he struggles to recreate what was taken from him. He finds some friends in the Venetian Republic, and after the initial shock recedes he begins to make a place for himself in the Old World.
In Volume 3 Lothar has almost completely recovered from his exile into the 10th Century. Now his ambition rules him and he gains his own realm and subjects as he strives to make the world more to his liking.