The Battle of the Frigidus took place in 394 AD between the forces of the Roman Emperor Theodosius I and the usurper Eugenius. This significant conflict occurred near the Frigidus River in present-day Slovenia. Theodosius aimed to restore unity to the Roman Empire and eliminate Eugenius, who had been supported by the powerful general Arbogast. The battle was marked by harsh weather conditions, with heavy rain and cold temperatures affecting both armies. Ultimately, Theodosius emerged victorious, solidifying his power and leading to the end of pagan practices in the empire. This victory also paved the way for the rise of Christianity as the dominant religion in the Roman world.