What Is Barbarian Invasion?

By SubRosa


Barbarian Invasion is the first expansion for Rome: Total War, and was released in September of 2005. Where the original game followed the time-frame of the rise of the Roman Empire – Barbarian Invasion is set during its fall, beginning in the year 363 C.E. and ending in 476 C.E.

Barbarian Invasion features several new enhancements to the game, including Religion, Hordes, Emergent Factions, Rebel Factions, and more. Each of which will be detailed further below.

Where RTW featured 103 territories on its Campaign Map, BI only possesses 72. Because of this many factions begin the game with only a single territory. This, along with territories being generally poorer than in RTW, significantly alters gameplay. The player will often have fewer troops than were available in RTW, and each battle will have greater impact. Money will be harder to come by, so the wise management of resources becomes more important as well.

Night battles are now possible. They can only be initiated by a General with the Night Fighter (or related) trait. While the army attacked must fight whether or not it has such a General leading it, reinforcing armies may only enter the battle if they also have a Night-Fighting General.

Generals can now be recruited from a city the same as regular units. There are also many new units, traits, retainers, even relics and weapons, all reflecting the very different time period. Some new special abilities have been added as well. Shield Wall is a new defensive formation that some units can form. This greatly increases their defense, but at the price of reducing their attack and movement. Schiltrom is another ability which allows a unit to form in a circular formation, making them impossible to flank at the price of sacrificing their ability to move. Finally, some units can now swim, adding an extra wrinkle to battles at rivers and on coasts.

Two new Historical Battles are offered as well. The first is The Battle of Chalons (The Battle of the Catalaunian Fields) between Atilla and Aetius. The second is The Battle of Badon Hill, a fantasy battle between Artorius Castus (better known as King Arthur) and the Saxons.


There are 21 factions in the game. 10 are playable from the start. Those listed under Unlockable can be made playable through a simple modification of the game files. The Non-Playable factions require much further modification to be played, as they are Emergent Factions (see below).

Playable Factions

  • Western Roman Empire
  • Eastern Roman Empire
  • Huns
  • Sarmatians
  • Vandals
  • Goths
  • Saxons
  • Franks
  • Alemanni
  • Sassanid Persia

Unlockable (by game modification) Factions

  • Roxoloni
  • Celts
  • Burgundians
  • Lombards
  • Berbers

Non Playable Factions

  • Romano-British
  • Slavs
  • Ostrogoths
  • Western Roman Rebels
  • Eastern Roman Rebels
  • Slave/Rebels


Hordes are a new and major factor in the game, meant to portray the migrations of many barbarian peoples that took place in the time period of the game.

Some factions have the ability to form a horde, either by choice when they have a single settlement, or forcefully when their last settlement is taken from them. This latter event does not destroy them as it would a normal faction, but instead automatically turns them into a horde.

When a faction hordes it gains a large number of new units in addition to those it had previously possessed. These represent common people who have abandoned their civilian pursuits and taken up arms for the migration. These horde units are denoted by a wheel symbol in the upper right corner of their unit cards.

There are many special rules that govern horde factions. First, when a faction hordes it no longer has to pay upkeep for any of its non-horde units, and it never has to do so for its horde units. Only mercenaries must be paid upkeep while a faction is a horde. However, hordes cannot retrain depleted units, nor train new ones until they settle. Because of this all hordes must eventually settle or face permanent destruction from attrition.

When a horde faction takes a city it is given two options to chose from – Occupy or Sack. If Occupy is chosen then the horde begins to settle down, starting with that city. If it Sacks then it massacres a large portion of the population, destroys the buildings, and takes all the loot it can find. If any mercenaries participated in the sack they will also take a share of plunder for themselves. Afterward the city then reverts to rebel ownership. Typically the horde faction will then move on, but it might want to attack and sack the city again to squeeze every last drop of denarii out of it.

When a horde faction does decide to settle down and chooses to Occupy there is no turning back. From that point on they can no longer Sack settlements, but rather will be presented with the normal 3 options of Occupy, Enslave, or Exterminate when taking a city. At this point they must also begin paying upkeep for all their permanent units.

Furthermore, they will immediately lose 1/3rd of their horde units, starting with those within or nearest the city taken. However, the faction will gain a special bonus, in that they will suffer no culture penalty for buildings in this first city they have Occupied. This only applies to the first city taken, making this a very important strategic consideration.

The second city that the faction takes (regardless of whether they Occupy, Enslave, or Exterminate), they will lose half of their remaining horde units (1/3rd their original force). Finally, when they take a third city all their remaining horde units will be disbanded.

When horde units are disbanded, their members are added to the population of the city taken in the first and second waves of de-hording. The final wave of de-hording is different in that the members of each unit are disbanded into the city which they are nearest to, rather than into the city taken.

At this point the faction has returned to being a regular faction. Note that if a faction is half-way through the processes of de-hording and it loses its cities through enemy conquest, it will horde all over again.

Factions capable of Hording

  • Huns
  • Sarmatians
  • Vandals
  • Franks
  • Goths
  • Ostrogoths
  • Roxolani
  • Slavs
  • Burgundians
  • Lombards

Emergent Factions

Barbarian Invasion includes emergent factions. These are factions which do not exist at the beginning of the game, but rather may emerge during the course of the campaign if specific conditions are met. Some are trigged when the campaign reaches a certain date. For example the Slavs appear in 410 C.E. Some appear if certain cities are taken, and some when a rebellion occurs in an existing faction.

Among these emergent factions are special rebel factions that appear whenever a Western or Eastern Roman Empire city rebels. Unlike the standard generic rebels which normally appear when a settlement rebels, these are full factions, with family members, the same recruitment and building options as their parent factions, capable of diplomacy, etc… The Ostrogoths are also a special rebel faction spawning in response to Goth rebellions.

Furthermore, Generals belonging to the Western and Eastern Roman Empire now have a loyalty rating. This determines the General’s likelihood of turning rebel himself. If he does, he will also take his army with him.


Barbarian Invasion features three Religions – Christianity, Paganism, and Zoroastrianism. All Generals belong to one of them, represented as a trait they possess. Each settlement will be made up of members of one or more of these religions. Exactly which ones depends upon a variety of factors.

Each settlement’s official religion is set simply by building the appropriate temple within it. This has the largest impact on the overall religious makeup of the settlement. However, that does not mean everyone in the settlement will belong to that religion. The presence of Generals and other characters also affects the religion of citizens, as does the religions of neighboring provinces. Even throwing gladiatorial games can affect the religious breakdown of a settlement. So often a city will have a large majority of people belonging to one religion, plus minorities belonging to one or both of the other religions as well.

Religion mainly affects the play of the game by adding an extra element of unrest in the populations of cities. When an element of a city belongs to a different religion than that of the temple within they will cause unrest. The amount of unrest is directly proportional to the percentage of the population belonging to the second religion. Combined with the regular reasons for unrest – squalor and buildings of different cultures – this can make some cities impossible to hold.