Unification Wars (Galactic Republic)

The Unification Wars were the series of conflicts fought between pre-Republic interstellar states. These conflicts were the decisive factor that led to the Core Worlds to develop the Galactic Constitution and the Coruscant Accords to merge into the Galactic Republic c. 25,000 BBY. Between then and the Wars' end, they served to expand the new Republic into the Colonies and beyond, beginning the gradual assimilation of the Galaxy into the Republic.

The Unification Wars began during the early years of the Expansionist Era. The Unification Wars may have included the First Great Schism (25,000 BBY) and the Tionese War (24,000 BBY).

Behind the scenes
The non-canon Book of Imperial Shuttle Plans: Cygnus Spaceworks mentions a conflict called the "Unification Wars of 3,817".