The Western Roman Empire, (along with its eastern counterpart, the Eastern Roman Empire) is a major opponent featured in numerous levels of the Attila the Hun campaign in the Age of Empires II: The Conquerors expansion and in the Alaric campaign, featured in the Forgotten expansion.
The main Roman player color is always blue in the Attila campaign, and the Romans are represented by the Byzantines civilization. However, the various Italian cities of the last mission are represented by various other factions, such as the Teutons.
On the other hand, the main Roman colors used for the Romans in Alaric is either red or orange, and are always represented by the Italians.
The Western Roman Empire can be found on the first, fourth, fifth and sixth Attila the Hun levels. It is only a minor opponent on the first level, Scourge of God, but is a more prominent force in the following levels. On the second and third levels of the campaign, The Great Ride and Walls of Constantinople, they are replaced by the Eastern Roman Empire, represented by various cities and factions. In the final level, Fall of Rome, the Western Roman Empire is in ruins, and Attila must proceed to the now shell of the former empire, destroying almost all cities in Italy in order to complete the level.
The Romans are also faced during the first, second and fourth levels of the Alaric campaign, but not during the third one (where the enemy is instead the Gothic chieftain Saurus). Instead of the attacks against the Eastern Roman Empire and Roman Gaul (modern day France), the main focus is the conquest of Italy and the Sack of Rome.
The Western Roman Empire is portrayed in its twilight, during the process of decline, failing to enforce its rule, its vast territory divided into several successor polities.
It has long lost the strengths that had allowed it to exercise effective control, and increasing pressure from the Huns and Germanic tribes also contributed greatly to its collapse, which marks the end of the Late Antiquity and the beginning of the Dark Ages.
In the Alaric campaign, the Empire's architecture is much more appropriate. Also featured are various structures typical of Roman architecture, such as the Arch of Constantine, Aqueducts and Amphitheatres.
During the Attila campaign, the Empire employs typical Byzantine troops, including Cataphracts, though in Fall of Rome, the various Italian cities employ units according to the civilization they are represented from.
During the Alaric campaign, the Empire fields troops typical of the Italians, including the anachronistic Condottieri. Apart from that, the missions feature certain Roman units, namely Legionaries and Centurions, to add some historical accuracy.
Also, the Western Roman Empire is allied with a number of civilizations; the Franks, Visigoths, Alans, and the Sassanid Empire. Germanic tribes frequently oppose the player, as Foederati or allied tribes, a notable case encountered in Emperor of the West, where Alaric must defeat the rival Gothic chieftain Saurus, who holds the city of Ravenna.