Over the four years the Alliance, one of the superpowers of the galaxy, was humbled by a race new to space with inferior technology. The arrogance of Alliance commanders lead to massive failures on every level and huge losses, in terms of manpower and military hardware, and their reputation as an unbeatable superpower lay in ruins and lead directly to the BuTani Overview.
The disastrous first contact with the Gryar is what led directly to the war.
Over the four years of the war there was an initial invasion by the Gryar, an initial skirmish with local forces, a second wave of reinforcements by the Gryar and then major attacks by Star Command, the first and second campaigns on Okudazin and the Liberation of Suanshi. While Suanshi was liberated the two attacks on Okudazin were unsuccessful and crippled Alliance forces.
The war ultimately only came to an end when Nikolai Takowyski convinced the Alliance to bring in their allies, the Imperial Oferan Empire, under the command of Auxor, whose massive capital ships were too much for the small Gryar starships and an armistice was put in place until a peace treaty ultimately lead to a lasting peace.
In terms of galactic scope the Gryar War was relatively small, consisting of only one star system (Boardene) and the surrounding area, however, the Alliance contributed a huge amount of resources into the war, as did the Gryar, and the repercussions of the war were still being felt on a galactic level 20-years later.
One of the concessions Star Command made after their failure was to design starships with more shielding around the bridge.
Events in the Gryar War will be covered by subsequent books in the Seraphic Chronicles series.