Clash of Empires: The Battle of Trebbia 218 BC

In this article I’m going to use the Clash Battle System to recreate the Carthaginian general Hannibal’s victory over the Romans at Trebbia in 218 BC. Trebbia is significant because it is the first major battle in which Hannibal demonstrated his military genius and it is the only battle in which his use of war elephants contributed to his victory. In fact, they were also used at Zama at the end of the Second Punic War (202 BC). However, that was a Carthaginian defeat.

Background

Rome’s designs upon Spain which was rich in resources and within the Carthaginian sphere of influence provoked the Second Punic War 218 – 201 BC. The Carthaginian general Hannibal decided to take the fight to Rome itself and marched an army of 20,000 infantry, 6000 cavalry and about 40 elephants across the Pyrenees and the Alps to arrive in northern Italy. Here the Carthaginian army was reinforced to nearly double its original strength by Celts from the Po Valley. They wanted revenge upon Rome for their earlier defeat and subjugation. A Roman army of some 40,000 men under the command of two consuls confronted the invaders on the west bank of the river Trebbia near the modern town of Piacenza. In the frigid conditions of late December, the two armies formed up on an open plain. Hannibal had picked his ground well and concealed an ambush force commanded by his brother Mago in a drainage ditch behind the Roman army. In the centre of his line Hannibal placed his expendable Celtic and Spanish troops while on their flanks he positioned his elite Libyan infantry in phalanx formation and reinforced by war elephants. On the opposing side the Romans adopted their usual array of three lines of heavy infantry in the centre and cavalry on the flanks. As predicted the serried ranks of Roman legionaries used brute force to punch their way through the Carthaginian centre. On the flanks the Libyans and elephants held. Meanwhile, Hannibal had used his superior cavalry force to neutralize the Roman cavalry while the ambush force blocked off any escape route to the rear. Now the Roman flanks disintegrated under the impact of the Libyan infantry and elephants. Thereupon, those Romans that pressed forward through the centre escaped while the rest of the army was slaughtered. The Romans lost about 30,000 troops while the Carthaginian losses were about 5000 men most of these being Celts and Spaniards that could be replaced. At Trebbia the Romans had a taste of what was to come namely the near extinction of Rome at the hands of one of the most brilliant military tacticians of the ancient world. 

Clash of Empires

Using the Clash of Empires rules the battle strength and capabilities of the belligerents can be shown as follows: -

Carthaginian Army

Mixed Army combination with a Combat Rating (CR) of ❷ for Primary Part-Standing, CR ❶ for Secondary Warband and Tertiary Allied Numidian Mounted Skirmishers, which based upon the number of army units i.e., 36 converts to a +13 Fighting Bonus (FB). Battle Dice 2D6 (highest scoring die only). Mixed Fighting Techniques (MFT) consisting of African Phalanx, Warband Battle Rush and Mounted Skirmishers which gives the Carthaginians a +6/+9 modifier to their Battle Dice score. The second modifier is used if FB greater than that of the opponent. For Battle Advantage Dice the Carthaginian army has 1D6+2 for Heavy Cavalry as well as the normal +1 to Initiative for cavalry and 1D6 for War Elephants. As for Hannibal he is ranked as a Great Commander and rolls 2D6 (highest scoring die only) for Initiative. Under Hannibal the Carthaginian army has a superior command structure +2 Initiative and for this battle Hannibal has decided to place 20% of his army’s FB that is +3 in reserve to protect vulnerable points in his battle line. This means that the normal -1 penalty to Initiative for unwieldy phalanx is negated. Therefore, the Carthaginian army rolls 2D6 +3 for Initiative.

Republican Roman Army

Part-Standing Army type with a Combat Rating (CR) of ❷, which based upon the number of army units i.e., 32 converts to a +16 Fighting Bonus (FB). Battle Dice 2D6 (highest scoring die only). Fighting Technique: Legion which gives the Romans a +2/+4 modifier to their Battle Dice score for Heavy Infantry. The second modifier is used if FB greater than that of the opponent. Also, a Part-Standing Roman Legion can save against defeat by rolling 5-6 on 1D6 which is owing to their Special Ability Relentless. They also have Medium Cavalry which gives them a 1D6+1 Advantage Die as well as the normal +1 to Initiative for cavalry. On the day of the battle command of the Roman army falls to the consul Titus Sempronius Longus. He is ranked as competent and rolls 1D6 for Initiative. Therefore, the Republican Roman army rolls 1D6+1 for Initiative.

Clash Battle System

After rolling for Initiative the Battle Roll for each army consists of the following procedure:

• Roll Battle Dice 2D6 (highest scoring die only)

• Plus, Combat Rating (CR) to Fighting Bonus (FB) (conversion dependent upon number of units)

• Plus, Battle Bonus calculation determined by army type and FB.

• Plus, Advantage Dice (representing a numerical, tactical or other special advantage)

Highest score wins and the difference between the two Battle Rolls determines the number of casualties.

Combat Rating to Fighting Bonus Conversion and Casualty Tables not shown.

Battle Log

Carthaginian

Initiative	Battle Dice (Modifiers)	CR to Fighting Bonus	Battle Bonus	Battle Advantage Dice	Total Score
2D6 +3 4 and 2 4+3 = 7	2D6 MFT (+6/+9) 6 and 4 (Highest die only) 6+6 = 12	❷/❶/ x 36 = +13 FB 13-3FB (Reserve)  = +10 FB	Evens Dice 2D6 5+3 = 8	Opponent outnumbered 1D6. Tactical Advantage 1D6 Heavy Cavalry 1D6+2 War Elephant 1D6 5+3+5+2 = 15	12+10+8+15 = 45

Republican Roman

Initiative	Battle Dice (Modifiers)	CR to Fighting Bonus	Battle Bonus	Battle Advantage Dice	Total Score
1D6 +1 = 5	2D6 Legion (+2/+4) 4 and 3 (Highest die only) 4+4 = 8	❷x 32 = +16 FB Relentless 5-6 1D6 = 3	No odds or evens 2D6 6+2 = 8	Medium Cavalry 1D6+1 5+1 = 6	8+16+8+6 = 38

Battle Bonus Calculation Table

FB	Warband	Feudal	Citizen	Part-Standing	Standing
1-4	1D3(1D6)	1D3(1D6)	1D3(1D6)	1D3(1D6)	1D6(2D6)
5-8	1D3(1D6)	1D3(1D6)	1D3(1D6)	1D6(2D6)	1D6(2D6)
9-12	1D3(1D6)	1D3(1D6)	1D6(2D6)	1D6(2D6)	2D6(3D6)
13-16	1D3(1D6)	1D6(2D6)	1D6(2D6)	2D6(3D6)	2D6(3D6)
17-20	1D6(2D6)	1D6(2D6)	2D6(3D6)	2D6(3D6)	3D6(4D6)
21-24	1D6(2D6)	2D6(3D6)	2D6(3D6)	3D6(4D6)	3D6(4D6)
25+	2D6(3D6)	2D6(3D6)	3D6(4D6)	3D6(4D6)	4D6(5D6)

(#D#) = Enhanced Battle Bonus on odds or evens Battle Dice.

For a Mixed Army Combination select the column to the left of the primary Army Type and use the bonus dice shown therein. Use unamended FB for calculation.

Note: - The Carthaginians win Initiative by 2 which yields a 1D6 Tactical Advantage. Making the most of their various Battle Advantages and achieving an Enhanced Battle Bonus of 8 the Carthaginians use their phalanxes and War Elephants to attack the Roman wings that disintegrate under the impact. Although the Roman centre manages to break through the Celts the rest of the army is annihilated. The Romans lose 75% of their army i.e., 24 units, whereas the Carthaginians lose 7 units. The War Elephants must save against loss on 4-6 on 1D6. A 3 is rolled so the elephants are destroyed and must be purchased again.

The Carthaginians win a decisive victory over the Romans at the Battle of Trebbia 218 BC. Figures by Irregular Miniatures from their 25mm Greek & Roman range. Painted by Silurian and from the author’s own collection. The numerical strength of each army is denoted by blank coloured poker chips. Game board from the Clash of Empires: The Hellenistic World Game.

The Celtic and Spanish warriors break under intolerable pressure from the compact ranks of heavy Roman infantry. However, the Roman flanks are soon assailed by the Carthaginian war elephants and African infantry which results in the bulk of the Roman army being destroyed. Figures by Essex Miniatures from their 15mm Ancients range. Painted by Silurian and from the authors own collection.  

Sources

Boulter, M. L. 2009/2025: Clash of Empires: The Hellenistic World. Silurian War Games Ltd.

Dupuy, R. E. and Dupuy, T. N. 1993: The Collins Encyclopaedia of Military History. Harper Collins Publishers.

Goldsworthy, A. 2001: Cannae. Cassell & Co.

Hackett, J. 1989: Warfare in the Ancient World. Sidgwick & Jackson Ltd.

Head, D. 1982: Armies of the Macedonian and Punic Wars 359 BC to 146 BC. A Wargames Research Group Publication.

Mellersh, H.E.L. 1995: Chronology of the Ancient World, 10,000 BC – AD 799. Helicon Publishing Ltd.

Wise, T. and Healy, M.1999: Hannibal’s War with Rome. The Armies and Campaigns 216 BC. Osprey Publishing Ltd.

Article Front Page Picture

Punic War, in which Romans and Carthaginians fought (3rd-2nd Century BC). After Alamy (IY04446764).