The story is staged in the distant future within our own Milky Way Galaxy, approximately in the 35th century. Unlike other science fiction stories, there are no alien civilizations. A portion of the galaxy is filled with terraformed worlds inhabited by interstellar traveling human beings. For 150 years two mighty space powers have intermittently warred with each other: the Galactic Empire and the Free Planets Alliance.
Within the Galactic Empire, based on 19th century Prussia, an ambitious military genius, Reinhard von Müsel, is rising to power. He is driven by the desire to free his sister Annerose, who was taken by the Kaiser as a concubine. Later, he wants not only to end the corrupt Goldenbaum dynasty but also to defeat the Free Planets Alliance and to unify the whole galaxy under his rule.
In the Free Planets Alliance is another genius, Yang Wen-li. He originally aspired to become a historian, and joined the military only because he needed money for tuition. He was rapidly promoted to an admiral because of his demonstrated excellence in military strategy. He becomes the archrival of Reinhard, though they highly respect one another.
As a historian, Yang often narrates the rich history of his world and comments on it. One of his famous quotes is: "There are few wars between good and evil; most are between one good and another good."
Besides the two main heroes, the story is full of vivid characters and intricate politics. All types of characters, from high nobility, admirals and politicians, to common soldiers and farmers, are interwoven into the story. There is a third neutral power nominally attached to the Galactic Empire called the Phezzan Dominion, a planet-state (city-state on a galactic scale) which trades with both warring powers. There is also a Terraism cult, which claims that humans should go back to Earth, gaining popularity throughout the galaxy. The story frequently switches away from the main heroes to the Unknown Soldier fighting for his life on the battlefield.
You may have heard of the highly regarded LotGH OVA anime series, you may even have already watched it. This is the original series of novels upon which the anime is based, of which the first 4 (at the time of writing) have been released in English.
LotGH is essentially a history book, but set in the far future instead of the past. Outside of the main 3-4 characters, the other characters are drawn in outline, and many things are implied more than outright stated. The main characters are better developed, especially the Galactic Empire's Reinhard, who is quite a mysterious character. You learn more
about him as the books progress and, despite his genius capabilities, he is also very human. On the other hand, the Alliance's Yang is the character most readers will likely sympathise with. However, it is soon shown that LotGH's universe features not black or white, but many shades of gray. There are no simple moral answers.
Personally I somewhat prefer the novels to the anime. This is for two reasons: The anime necessarily leaves out some details that aren't as important, but yet are still fascinating for political and historical interests. The anime doesn't reveal the universe's backstory until a while later which may leave you confused at first. Also, I found events easier to follow in the novel than the anime. However, if you experience one it's still fully recommended to also experience the other medium.
This series is an absolute must read for fans of stories focusing on politics, military, and history buffs. It is also recommended for anime watchers or those who tried to get into the anime but found it antiquated or hard to follow.
The OVA format was, and in many ways still is, one of the most important forms of distribution for anime companies. Even with the dawn of the internet and popular anime streaming services, the OVA format is still going strong. This is all, in large part, because of a certain show...