When Alexander the Great died in Babylon, still only in his early 30s, in 323 BC, he left behind a vast kingdom, sprawling across three continents, but no suitable heir. The Macedonian king’s dazzling conquest of the Persian Empire had won him unimaginable wealth and territory, and, suddenly, all of it was up for grabs.
In the decades that followed, his generals and their sons competed viciously and bitterly, as each sought to position himself as Alexander’s sole successor. This was the start of the so-called Hellenistic period, which lasted from Alexander’s demise until the suicide, in 30 BC, of the renowned queen Kleopatra VII, known to posterity as Cleopatra.
By the early 3rd Century BC, a new world order had emerged. Broadly, it consisted of three dynasties, each presiding over a colossal kingdom. The Ptolemies ruled Egypt. The Seleucids held Syria. Meanwhile, in Macedonia, the Antigonids were in control. These three powers dominated the eastern Mediterranean until the arrival of the Romans.
Akropolis
The hill town of Pergamon first came to prominence as a refuge for Barsine, with whom Alexander the Great had a son named Herakles (Credit: Alamy)
In time, though, several smaller but still important kingdoms, such as Bactria in present-day Afghanistan, broke away. And it so happens that we know more about the glittering capital of one of them, the realm of Pergamon in western Turkey, than any other Hellenistic city.
“We think of Athens, Rome and Istanbul as great cities,” says Carlos A Picon, the curator of a major, ongoing exhibition devoted to Pergamon at the Metropolitan Museum of Art in New York. “But, during the Hellenistic era, there were really only a handful [of important royal capitals] – and Pergamon was up there.”
‘Very Game of Thrones’
In part, we are familiar with Pergamon thanks to a quirk of archaeology. Other tantalising Hellenistic cities remain impossible to excavate. “Antioch seems to be lost forever,” Picon says. “Alexandria is now mostly underwater. Syracuse, in Sicily, is under the present city. But Pergamon was abandoned, more or less. And, since the 1870s, it has been excavated by the Germans, so it’s really the only Hellenistic city about which we know a fair amount.”
Ancient city
We know more about the glittering capital of Pergamon in western Turkey than any other Hellenistic city (Credit: Alamy)
As a result, Pergamon is crucial for understanding the scope and sophistication of the Hellenistic world. “If we have this much from Pergamon,” Picon tells me, “just imagine the amount of evidence from other sites that hasn’t survived.”
Pergamon is crucial for understanding the scope and sophistication of the Hellenistic world 
Situated 15 miles (24 km) inland from the coast of north-western Asia Minor, and surrounded in antiquity by oak forests, the hill town of Pergamon first came to prominence as a refuge for Barsine, the wife of a defeated Persian general, with whom Alexander the Great had a son named Herakles. Its easily defended position, on top of a massif, made it a natural fortress. As a result, after Alexander’s death, one of his Macedonian generals decided to store his war booty, some 9,000 talents of silver, on its acropolis.
Thanks to good fortune, as well as deft political manoeuvring, the opportunistic guardian who had been left in charge of this treasure, Philetairos, was eventually able to use it to found a dynasty of his own. Named after his father, Attalos, they were known as the Attalids (282-133 BC). In time, the Attalids reduced their dependency upon the Seleucids, and became a world power in their own right. It was all very Game of Thrones.
Mosaic
The frieze of Pergamon’s Great Altar was described by Andreas Scholl as “one of the finest works in the history of world art” (Credit: Alamy)
In order to signal their new self-image, the Attalids transformed the impregnable citadel of Pergamon into a radiant metropolis of learning and culture, designed to rival Classical Athens at its height during the 5th Century BC. This message was made plain by a colossal marble statue of Athena, recovered from the Pergamene Library, and currently on display in New York. Carved around 170 BC, it alluded directly to the “Athena Parthenos”, the famous cult statue by the Greek genius Pheidias, which once stood on the Athenian Acropolis.
The great library was only one element in a magnificent building programme initiated by the Attalids, who also constructed a theatre and a gymnasium, and redesigned the city’s sanctuaries. They enriched their palaces with Classical paintings and sculptures, and commissioned lavish mosaics, for which Pergamon became renowned.
Library
The great library was one element in a magnificent building programme initiated by the Attalids that included a gymnasium and a theatre (Credit: Alamy)
Moreover, they raised spectacular monuments honouring their victories over the Galatians, a tribe of Celtic mercenaries who had been ravaging Asia Minor for years. Indeed, the decisive victory over the Galatians of Attalos I during the 230s BC earned the dynasty royal status. It also ushered in the period of Pergamon’s greatest influence and prosperity.
The new Athenians
One monument, above all, expressed the splendour of the Attalids: Pergamon’s Great Altar. This unique structure, dedicated during the 2nd Century BC, consisted of an Ionic colonnade above a vast pedestal or podium, resting on a five-stepped platform. The pedestal provided the focus of the monument, since it was decorated with a dramatic (and unforgettable) frieze, carved in high relief. Writing in the catalogue accompanying the exhibition at the Met, Andreas Scholl, director of the Berlin State Museums where the reconstructed frieze can be seen today, calls it “one of the finest works in the history of world art”.
The Great Altar was brute power masquerading as fine art 
More than 300ft (91m) long, and almost 8ft (2.4m) high, it depicts a terrifying battle between the Olympian gods and the primordial giants who challenged their supremacy. The tumultuous action encompasses more than 100 over-life-size figures, twisting and turning with startling energy (some giants actually emerge from the frieze onto the altar’s steps), all executed in a thunderous baroque style.
Altar
Above all monuments, Pergamon’s Great Altar expressed the splendour of the Attalids (Credit: Alamy)
The message, for Hellenistic viewers, would have been clear. The Olympians were aligned with the Attalids – who, according to Picon, considered themselves the “new Athenians” – while the giants were their trampled enemies. The Great Altar was brute power masquerading as fine art.
Today, it epitomises the opulence and ambition of Hellenistic art, which is also attested in the Met’s show, albeit on a smaller scale, by luxurious jewellery, diadems, glass and silverware, charismatic bronze busts, and staggering cameo gems. The latter were a Hellenistic speciality, often bestowed as sought-after diplomatic gifts.
Hair ornament
Luxurious jewellery, diadems, glass and silverware, charismatic bronze busts and cameo gems show the opulence of Hellenistic art and design (Credit: Athens, Benaki Museum)
Despite boasting all of the splendid trappings of power, though, Pergamon could not sustain its political pre-eminence forever. The last of the dynasty’s rulers, Attalos III, was a paranoid botanist who died of sunstroke, in 133BC, while dabbling as a sculptor, working on a tomb for his mother. Unusually, he bequeathed his empire to the Roman Republic – a surprising move perhaps designed to dissuade the bullish Romans, who had a reputation for sacking sparkling Hellenistic centres such as Syracuse, from wrecking Pergamon.
For Picon, the interaction between Rome and the Hellenistic kingdoms of the eastern Mediterranean was all-important. “Rome sucked the life out of the Greek world,” he explains. “The Italian peninsula was inundated with loot from the East, and all that wealth was funnelled into Rome. Initially, the Romans found the luxury of the East alarming, distasteful, a little effeminate. But gradually they became completely Hellenised. By the time of Hadrian, the Romans were more Hellenic than the Greeks.”
Cameo
Cameos were a Hellenistic speciality, often bestowed as sought-after diplomatic gifts (Credit: Antikensammlung, Kunsthistorisches Museum, Vienna)
Pergamon, of course, played a decisive role in this process of acculturation. “Thanks to their largesse and good fortune,” says Picon, “the Attalids were able to beat all the old enemies of Greece. They found themselves the saviours of the Greek spirit, as it were, and were incredibly proud to uphold the Hellenic tradition.”
He continues: “Rome’s empire, of course, was considerably larger, and lasted much longer, than Pergamon’s: in the end, Rome held sway over the entire Western world for three centuries. But Rome couldn’t have done that without absorbing this giant wave of learning and heritage from the Greek East.”
Alastair Sooke is Art Critic of the Daily Telegraph