Herakles and Iolaus

John II directing a siege, from a French MS

In summer 1137 John II arrived outside the walls of Tarsus, an ancient city in Anatolia first conquered for the Roman Empire by Pompey the Great in 67 BC. The emperor was joined by the Frankish princes, Raymond of Antioch and Joscelin of Edessa, who came to offer their homage and help him recapture the city.

John had no desire for unnecessary bloodshed. He asked the citizens to surrender, calling on their shared Christianity as well as pointing out that resistance was futile: his combined army of Roman and Frankish troops had Tarsus completely surrounded, so there was no escape.

When the citizens refused, John brought up his siege weapons, described as 'thunderbolts' by the poet Italikos. After a brief bombardment, the citizens came to their senses and decided to surrender after all. John was merciful, making them his allies. Italikos compared John favourably to Alexander the Great, who had slaughtered the entire populations of cities that resisted him. 

Detail of Alexander from the Alexander Sarcophagus

However, the emperor's work was not done. Although the city had surrendered, the garrison still held out at the acropolis. Another Roman poets, Basilakes, described these men as heavily armoured, arrogant barbarians, who chose to resist their lawful emperor despite being 'the countrymen of Saint Paul'. 

To cow them into surrender, John once again brought up his siege weapons. He entrusted this task to his son and co-emperor, Alexios, the young man's first battlefield command. The poets compared the emperor and his son to the ancient Greek heroes, Herakles and Iolaus: the latter was nephew, charioteer and companion to Herakles. In Greek legend they defeated the monstrous Hydra, with Iolaus cauterising each neck as Herakles beheaded it (see below).

Faced with this show of strength, the 'barbarians' in the acropolis also surrendered. After securing the city, John moved to capture more fortified settlements, including Adana and Mopsuestia. During these operations he delegated another task to his heir, sending Alexios off to capture the castle of Gastin. 

Tarsus and Adana were located on the plains, and made relatively easy targets for John's artillery. The citadel of Mopsuestia, however, presented a more formidable obstacle. This occupied a high ridge in the foothills of the Taurus mountains, and might have given the emperor serious trouble. Fortunately, the sheer size of his army, plus the merciful treatment of those who had previously surrendered, persuaded the defenders to submit without a fight.  

With these victories under his belt, John now turned his attention to Anazarbos, the chief city of Armenian Cilica.