Japanese

銀河英雄伝説外伝　新たなる戦いの序曲[オーヴァチュア]

English

Ginga Eiyuu Densetsu: Arata Naru Tatakai no Overture

Based on a series of sci-fi novels, this series tells the story of a massive conflict between the Prussia-like Galactic Empire and the Free Planets Alliance. It describes all levels of the war, from the tactical to the strategic, but focuses most on the two opposing militaries' leaders: Reinhard Von Lohengram and Yang Wen-Li.(Source: AniDB)