Battle of Dertosa The Battle of Dertosa , also known as the Battle of Ibera , was fought in the spring of 215 BC on the south bank of the Ebro River across from the town of Dertosa . A Roman army , under the command of Gnaeus Cornelius Scipio Calvus and Publius Cornelius Scipio defeated a similarly sized Carthaginian army under Hasdrubal Barca . The Romans , under Gnaeus Scipio , had established themselves in Hispania after winning the Battle of Cissa in 218 BC . The expedition of Hasdrubal Barca to evict them had ended in the defeat of the Iberian contingent of the Carthaginian navy at the Battle of Ebro River in 217 BC . Hasdrubal launched another expedition in 215 BC , but the defeat at Dertosa cost the Carthaginians a chance to reinforce Hannibal at a critical juncture , and the Romans gained the initiative in Hispania . The Scipio brothers continued with their policy of subjugating the Iberian tribes and raiding Carthaginian possessions . After losing of most of his field army , Hasdrubal had to be reinforced with the army that was to sail to Italy and reinforce Hannibal . Thus , by winning this battle , the Scipios had indirectly prevented the situation in Italy from getting worse in addition to improving their own situation in Iberia . This battle also demonstrates the danger of implementing the double envelopment tactic . Strategic Situation . Italy . After the Battle of Cannae , several towns in Campania , Samnium , Lucania , Apulia and Bruttium had defected to Carthage . Hannibal spent the period 216 - 215 BC trying to secure a seaport to ease his communication with Carthage by attacking Neapolis , Cumae and Nola , all unsuccessfully . A detachment under Mago Barca had secured objectives in Lucania and Bruttium . Leaving Hanno the Elder in command of this army in Bruttium , Mago sailed to Carthage to obtain reinforcements . The Romans had fielded several armies , which followed a strategy of avoiding Hannibal in the open field and striking at his allies whenever possible . The main Roman army under the dictator M . Julius Pera was guarding the direct approach to Rome in southern Latinum . Marcus Claudius Marcellus had battled Hannibal at Nola and also prevented Neapolis from falling to the Carthaginians . The Master of Horse , T . Sempronius Gracchus , was on the field with a third army in Lucania . Other legions guarded against any Gaulish uprisings in north Italy . Sardinia . The legion posted in Sardinia suffered from sickness . The praetor , Muscius Scavola , had to collect pay and provisions for the troops locally . This had caused unrest among the Sardinians , and Hampsicora , a Sardinian chieftain , was fomenting rebellion among the locals and had requested Carthaginian aid . Africa . Carthage raised 15 , 000 infantry , 1 , 200 cavalry and 20 elephants under the command of Mago , which was to sail to Italy escorted by 60 quinqueremes . Upon receiving the appeal from Sardinia , a similar sized army was raised under Hasdrubal the Bald , for an expedition to Sardinia . Iberia . Hasdrubal had been on the defensive since the defeat of his fleet at Battle of Ebro River in the spring of 217 BC . He had left Boaster , a subordinate commander , with a force to guard the Ebro line against any Roman encroachment . Boaster had retreated when the Romans had crossed the Ebro . Furthermore , he was tricked into surrendering the Iberian tribal hostages held at Saguntum to the Romans by an Iberian chieftain named Abylix . This caused revolts in Barcid Iberia , especially among the Trudetani tribe near Gades in 216 BC . Hasdrubal received 4 , 000 foot and 500 horsemen , with orders to march to Italy after securing Iberia . The better part of 216 BC was spent in subduing the Iberian tribes , with little effort made to confront the Romans . Gnaeus Scipio had received 8 , 000 reinforcements under his brother Publius Scipio after the battle of Ebro River . The brothers enjoyed proconsular rank , and exercised joint command . The brothers adopted an aggressive naval strategy given the destruction of the Carthaginian navy , raiding Barcid possessions in Iberia and Balearic Islands . The Scipios also recruited auxiliary troops from Iberian tribes , garrisoned towns to expand their operational sphere , consolidated their hold north of the Ebro River and dealt with tribal unrest there . They also encouraged Iberian tribes friendly with the Romans to raid tribes loyal to Carthage beyond the Ebro . Prelude . In early 215 BC The Romans crossed the Ebro River in force and laid siege to Ibera , a small Iberian town allied to Carthage . Leaving Himilco in charge at Cartagena , Hasdrubal marched north with his field army to the Ebro . However , he chose not to cross the Ebro to raid the Roman possessions nor did he attack the Roman army besieging Ibera . The Carthaginian army besieged a town allied with the Romans across Dertosa instead . The Scipios lifted their siege and moved to engage Hasdrubal . Thus , Hasdrubal had gained the strategic initiative . He had aided his allies by forcing the Romans to lift their siege and face the Carthaginian army on a site of his own choosing . The opposing armies encamped on a plain between Ibera and Dertosa within five miles of each other . After five days of skirmishing , the commanders drew out their armies for battle . Opposing Armies . The Roman infantry consisted of two Roman legions with a total of 10 , 000 soldiers , and 18 , 000 allied Italian troops . The cavalry was made up of 600 Roman and 1 , 800 Italian heavy horsemen . The Romans also had recruited an auxiliary force of 2 , 000 Iberian footmen and 400 heavy horsemen . Hasdrubal had 15 , 000 Libyan spearmen , 1 , 000 mercenaries ( mostly Ligurians from Italy ) and 8 , 000 Iberian troops for his infantry . The Carthaginian cavalry was made up of 450 Libyan / Punic and 1 , 200 Iberian heavy horsemen and 2 , 300 light Numidian horsemen . The Carthaginian army also had 20 elephants and 1 , 000 Balearic slingers . Deployment before Battle . The Romans posted their troops in their traditional manner , with the cavalry on the wings and the infantry in the center . The Roman and Iberian horse was placed on the right wing , the allied Italian horse on the left wing . The infantry line had the Italian troops on the wings next to the cavalry , and the Roman legions were posted in the center . Two thousand Roman / Italian troops and the Iberian infantry guarded the Roman camp . Hasdrubal placed the Libyan and Iberian horse on his left wing facing the Roman / Iberian horse , and the Numidian light horse on his right wing facing the allied Italian horsemen . Next to the Iberian cavalry contingent , Hasdrubal placed a phalanx of Libyan infantry , backed up by mercenaries , facing the Italian foot , and another phalanx of Libyan foot was placed next to the Numidian horsemen on the Carthaginian right wing , also facing Italian foot . Between the Libyan infantry phalanxes in the center of the Carthaginian infantry line , facing the Roman legions , was a thinned out Iberian infantry line . The elephants were divided into two groups of 10 and placed in front of the cavalry on both of the wings . The Balearic slingers formed a skirmish line in front of the infantry . Two to three thousand troops were left to guard the Carthaginian camp . Battle . Phase 1 . After a brief skirmish between light troops , the Roman legions in the center charged the thinned out line of Iberian infantry opposite them , and having the advantage of both number ( 10 , 000 against 8 , 000 ) and formation depth , drove back the Iberians almost instantly . However , this is an integral part of the double envelopment tactic Hasdrubal was trying to implement . The Carthaginian elephants placed on both the wings charged the Roman and Italian cavalry opposite them . The charge proved ineffective , the Italian and Roman horsemen were not disrupted , and the elephants played no further role in the battle . The Italian infantry formations closed with the Libyan formations opposite then in support of the Romans attacking the Iberians . Phase 2 . The Libyans and mercenaries placed on the flanks of the hard pressed Iberians charged the Italian infantry opposite them , and despite their advantage in numbers ( 16 , 000 against 18 , 000 ) , the Italians were pushed back . Unlike Cannae , the Libyans did not outflank the Romans . The Carthaginian cavalry placed on the wings , on the flank of the Libyans closed with the Roman and Italian horsemen opposite them . Despite having the advantage in numbers on both wings ( 1 , 600 Libyan / Punic and Iberians faced 1 , 000 Roman / Spaniards on the left of the Carthaginian line and 2 , 300 Numidians faced 1 , 800 Italian horsemen on the right of the Carthaginian line ) , the Carthaginian horsemen were unable to drive the Romans from the battlefield . An indecisive skirmish developed on the both wings of the armies between the opposing cavalry , with neither side gaining any advantage . At this point , the Iberian infantry on the Carthaginian center line collapsed , and began to flee the battle . Phase 3 . At Cannae , the center of the Carthaginian infantry line had also collapsed under Roman infantry assault . But Hannibal had managed to win the battle as his infantry had outflanked the Romans on both sides , and his cavalry , after driving their Roman opponents from the field , had attacked the Roman infantry from the rear ( or like the battle of Trebia where Mago ' s ambushing troops were also able to attack the Roman infantry in the rear ) . Hasdrubal had no ambush in place at Dertosa , but the Libyans had been driving the Italian infantry back when the Iberians at the center had collapsed . The Carthaginian cavalry , seeing their infantry center break and run , broke off their skirmishing with their Roman counterparts and also fled the battlefield . The Roman infantry , after scattering the Iberians , returned to help the Italian infantry . The Libyan infantry managed to put up a hard resistance , inflicting and suffering heavy casualties before being routed . Aftermath . Hasdrubal survived the battle with most of his elephants and cavalry , and a few infantry ( mostly Iberians ) . The Roman pursuit was not vigorous enough to repeat their success after the Battle of Cissa . The Romans managed to storm the Carthaginian camp , after Hasdrubal had hastily evacuated his soldiers . The provisions and booty fell into the hands of the victorious Romans . The shattered Carthaginian army retired to Cartagena , leaving the Romans firmly established south of the Ebro . Hasdrubal would be reinforced by two armies under Mago Barca and Hasdrubal Gisco to keep the Romans in check and keep the Carthaginian possessions in Iberia under control . The Carthaginians would not mount any effective campaigns north of the Ebro again , and would be fated to battle the Romans until 205 BC for the control of Iberia with varying success . The Scipio brothers did not mount a vigorous pursuit or an immediate campaign against the Carthaginians immediately after their victory . They chose to follow their strategy of mounting raids , instigating Iberian tribes to rebel , and building up their power base . The Scipios would receive no reinforcements from Italy for the remainder of their command in Iberia . They would fight the Barca brothers and Gisco with varying results until 212 BC , when they launched a major campaign leading to the Battle of the Upper Baetis . Importance . Hasdrubal had tried to imitate the tactics used by Hannibal at Cannae . While Hannibal had brought about a spectacular victory , Hasdrubal had suffered a shattering defeat . Some of the factors for this contrasting result are : Strategic importance . Although the Battle of Dertosa is not given the same importance as the Battle of the Metaurus , it had a critical influence on the strategic course of the war .