The Hegemony of Ptolemaic Egypt and Ascent of Bactria (246 BC- 201 BC)
Ever since the death of Alexander the Great, the dynasties that formed in the wake of his conquests battled furiously with each other for supremacy. While the two greatest of these dynasties were the Ptolemaic dynasty in Egypt and the Seleucid dynasty in Babylon, a general balance of power had settled across the eastern Mediterranean, as no single monarch could achieve supremacy, as the others would rally against any that proved too mighty. The constant warfare did seem to ebb when those two powerful dynasties established a peace treaty in 253 BC, with the daughter of King Ptolemy II Philadelphus of Egypt, Berenice Phernophorus, married to the Seleucid King, Antiochus II Theos, becoming his queen after he set his previous queen, Laodice, aside. There were few suggestions that such a marriage could form a long-lasting alliance, as the two kingdoms were natural rivals, but few could have predicted that the marriage itself would so quickly trigger a war between them.
Hellenistic World, c. 250 BC
In 246 BC, Ptolemy II died and was succeeded by his own son, Ptolemy III Euergetes. When news of this death reached Antiochus II, he immediately repudiated his marriage to Berenice and returned to his first queen, Laodice. The rejected queen and her twin children, a boy named Antiochus and a daughter named Arsinoe, might not have been in danger immediately, despite the political fall from grace, but Antiochus himself died shortly after rejoining Laodice in Ephesus. The restored queen quickly gathered support for her own sons, Seleucus and Antiochus to succeed him as co-rulers, rather than the infant Antiochus by Berenice. Of course, as in any monarchy, there was little enthusiasm at the prospect of a child monarch, so most of the aristocracy supported Laodice, and conspirators in Antioch soon moved against Berenice and her children. The unwanted branch of the royal family came very close to being murdered, but loyal retainers were able to spirit them out of Antioch and ultimately onto a ship, bound for Alexandria. Though the great phalanxes had yet to gather, the Third Syrian War, also known as the Laodicean War, had begun.
Bust of Ptolemy III Euergetes
Both realms fought almost entirely with mercenary armies composed primarily of Greek Phalangites. Neither the Seleucids or Ptolemies had any interest in conscripting the natives of the lands they ruled, as military service was, as in all ages, ultimately synonymous with power. However, in most other respects, the two kingdoms were very different. The Seleucids ultimately ruled a cosmopolitan empire, not so different than the Achaemenids before them, and their territory stretched from Asia minor to the Himalayas. The Ptolemies, on the other hand, ruled Egypt from their capital at Alexandria, and projected power out into the Mediterranean from that capital. In many ways, they were the rulers of a great city-state that could hold power over the Nile Valley through force of arms and the sponsorship of the Egyptian religion.
Hellenistic Anatolia
Though the two sides were relatively evenly matched, the Ptolemaic armies quickly gained the upper hand in the fighting. Ptolemy III had placed his armies under the command of Xanthippus of Sparta - the very same general who had fought and lost against the Romans for Carthage. Seleucus, on the other hand, had to share control with his brother, Antiochus, and the two struggled to cooperate. While the co-rulers squabbled, the Ptolemaic armies were able to seize Antioch and the surrounding regions of Syria, and they then marched on Babylon itself before the year had ended. While Ptolemy occupied the ancient capital, he crowned his nephew Antiochus as king of Babylon, conveniently shearing off the Mediterranean reaches of the Seleucid Empire from the kingdom he promised his nephew.
At this time, Anatolia was as fragmented as any region could be, though the Seleucids still were the most powerful force in the region. Seleucus attempted to win over allies in the region, but he was betrayed by his own brother, who decided that he preferred sole rule of Anatolia to co-rule of a larger empire with his brother. Antiochus was now the Seleucid monarch that other rulers treated with, and he brought together many allies, threatened by the successes of the Ptolemies. Pontus, Bythinia, Armenia, and Macedon allied themselves with Antiochus - though Antigonus II Gonatus of Macedon had already joined in the war on the Seleucid side, he simply began to fight alongside Antiochus. Ptolemy was not without his own allies in Anatolia, and chief among them were Pergamon and Rhodes, as well as the recently arrived Galatians.
While the fighting dragged out in Anatolia, Seleucus strove to regain his capital and push back into Syria. While he gathered his forces to do so, his eastern territories began to slip away in 244 BC, as Diodotus, the satrap of Bactria, declared himself king, while Andragoras, satrap of Parthia, did likewise. It seemed that the Seleucid Empire was completely dissolving around the unfortunate ruler, and indeed, it truly was. Seleucus maintained control of the Persian heartland, but after facing defeat while trying to retake Babylon in 242 BC, he bowed to the reality of the situation before him and made peace with Ptolemy. His treacherous brother fared less favorably, and Antiochus was killed in his sleep the following year, the war still dragging on in Anatolia.
Ptolemaic Egypt was the greatest victor of the war, gaining all of Syria to its direct rule. Babylon was ruled by the young nephew of Ptolemy III. Ptolemaic allies in Anatolia expanded their territories, with Pergamon securing its surrounding lands and Rhodes expanding onto the mainland itself. Macedon had managed to push Ptolemaic power entirely out of the Aegean, but gained little else. Persia and the lands to the east were the least touched by the war, but they would see their own battles soon enough.
Ptolemy III was supreme in the eastern Mediterranean, but he was not invincible. During the war, the Nile was not flooding as it usually did, causing severe economic hardship in the heartland of his empire. Though none at the time could have understood it, the lack of flooding was possibly due to severe volcanic eruptions elsewhere in the world, disrupting the rainfall in the headwaters of the Nile. These conditions had already begun early in the war, and had Seleucus and Antiochus been able to coordinate their opposition to Ptolemy, they likely would have been able to recover the majority of their losses.
As it was, Ptolemaic control was largely limited to the gains in the first year of the war. This still resulted in a vastly expanded domain, and Ptolemy made great use of this by importing grain to Egypt from the other regions in his domain - particularly his new Babylonian vassal - during the famines that followed. Further military expansion was impossible at the time, as the military was primarily focused on maintaining control within the Nile valley. If any of the neighboring powers had been in better condition to contest the Ptolemaic expansion, it is likely that their territorial gains would have lost in the following years.
Ptolemy’s rival, Seleucus, was faring far worse. Shorn of the agricultural heartland of Mesopotamia, his kingdom was contained to Persia itself, and he faced serious threats on many fronts. With the loss of Bactria and Parthia, his northeastern frontier was insecure, and the following years were spent securing his hold on his remaining territories. Andragoras, the rebellious satrap of Parthia suffered when the Parni, one of the steppe tribes of the Dahae confederation, invaded his lands in 237 BC. The Parni, under their leader Arsaces, conquered the rest of Parthia over the next few years, with Andragoras dying at some unknown point in the period. The Parni continued their expansion against both Persia and Bactria, until Seleucus secured a victory against them in 231 BC and was able to sign a peace with them, hoping that he might use their cavalry as mercenaries against his other foes. This left only the Bactrians, under Diodotus’ son, who styled himself Diodotus II.
Diodotus II faced considerable challenges in holding back the Parni, and almost the entire resources of his kingdom were dedicated to recruiting mercenaries from across the Hellenistic world to hold his territory. It would be to one of commanders that Diodotus would fall, rather than the Parni. The Hellenistic kingdoms were prone to coups, especially the younger ones that lacked institutional legitimacy or a history of victories. Diodotus had neither, and when a young mercenary commander named Demetrius started to secure a string of victories against the Parni, the king’s position was very insecure.
Bust of Demetrius I Soter
Demetrius was born sometime around 255 BC, in Anatolia, and had first fought in the Syrian War (fighting under Xanthippus), before heading further east as the company in which he was employed was hired by first Seleucus and ultimately, Diodotus. This provided the young man with plenty of experience against the Parni, and he rose quickly through the ranks. While in service to the Bactrian king, he began to lay out his own plans for a revolution in military warfare. He was every much the student of Philip and Alexander as any Hellenistic officer, and saw an opportunity to further develop their combined arms tactics. To do so, he needed a secure supply of steppe archers to rival the Parni, and found them in one of their rival Dahae tribes, the Pissuri. Demetrius would actually go on to marry the daughter of a leading Pissuri chief, Arsaces (not to be confused with the Parni ruler, Arsaces, who was styling himself king of Parthia by this time).
Rather than use the Hellenistic Phalanx as a tool with which to pin down an enemy army, as Philip and Alexander did, Demetrius would use the heavy infantry as a mobile fortification, able to secure key points on the battlefield and deny them to enemy. Meanwhile, the steppe cavalry would bring the battle to their opponent, with the archers disrupting their formations or wearing them down with continual volleys, while the heavier cavalry would follow through against any weak points. The key to the overall battle plan was continual but cautious offense. When Demetrius was in a position to use these tactics against the Parni, they were eminently successful, and the young commander was able to secure Bactria from the invaders, with peace being established in 225 BC. Just in time for the Parthian kingdom to invade Seleucid Persia upon the death of Seleucus, who was succeeded by his son Alexander, who took the name Seleucus for himself, reigning as Seleucus III.
In the same year, Diodotus was overthrown in a coup as Demetrius took control of Bactria, styling himself king, with the support of the army he had built. There were enough Greco-Macedonian cities in Bactria that he could recruit his infantry primarily locally, which was essential for him as the Parni of Parthia would defeat the remains of the Seleucid Empire in Persia by 220 BC, the year in which Arsaces’ brother, Tiridates, defeated and killed Seleucus III in battle. Bactria was effectively cut off from the rest of the Hellenistic world, but that mattered little to Demetrius. In Bactria, he was building upon Alexander the Great’s dream of a fusion of cultures, combining the urbanized and infantry-focused Greek traditions with the nomadic cavalry tradition of the steppe. He spent almost as much time focusing on the integration of Pissuri and Greek leaders, sponsoring marriages between the two groups, as he did campaigning against his enemies.
Demetrius did more than simply follow in Alexander’s footsteps in approach to culture and innovative tactics, and claimed to be a descendent of the great conqueror himself. Officially, Demetrius’ pedigree was that Alexander IV, his son, was secretly married to a princess in Anatolia (supposedly an Achaemind) shortly before his untimely death, and she bore him a son posthumously. This boy, Amyntas, was Demetrius’ grandfather. The genealogy was very unlikely, not only because there was no record of it whatsoever prior to Demetrius’ proclamations, but also because of the extreme youth of Alexander IV at the time of his death, no older than 14. However, it was not strictly impossible, and the claim of descent from Roxana bolstered Demetrius’ reputation in Bactria itself.
Demetrius would go on to campaign vigorously, claiming that he was restoring the Argead Dynasty to its rightful place as the only true heirs to Alexander’s legacy, and his continual victories were enough to convince many contemporaries that perhaps his supposed lineage was true. In the end, it was no less probable than the many kings declared to be the children of gods or gods themselves. His victories included conquering Sogdiana by 221 BC from a rival named Heliocles, Arachosia and Gandhara from the floundering Mauryans in 215 BC, and then Ferghana and Chorasmia in 211 BC. His approach was almost entirely opposite that of his claimed ancestor, as Demetrius campaigned in a fashion similar to how he fought his battles: he wished to wear out his enemies while exposing his own army to as little risk as possible. While some of his men may have wanted greater glory, few could argue with the results and the fact that they consistently could return to their homes and families. The rest of his campaigns were largely focused against the Parthians, gradually pushing their borders ever westward every campaign season.
Achaemenid Empire (for reference)
Demetrius would die peacefully in 201 BC after securing Hyrcania from the Parthians and historians would refer to him as Demetrius I Soter of the Bactrian Empire. His eldest son, Alexander V, would succeed him at the age of 24, only 4 years older than Alexander the Great had been when he succeeded Philip II. The empire he inherited stretched from the Caspian Gates in the west to the Jaxartes river in the north, the headwaters of the Indus in the east and the Gedrosian desert in the south. In the court at Bactra (the capital of Bactria) and the neighboring courts, there was wonder as to whether this young king would surpass his father, as his namesake had surpassed his own.
Campaigns of Alexander the Great (for reference)
Afterword
The Third Syrian War that I've chronicled here is pretty similar to history, except that I take it as an opportunity to totally screw over the Seleucids by giving Ptolemy a solid chance to prop up his nephew in Babylon. Which was really just an excuse for me to pump up Bactria (and, also, to play around with the Eastern Mediterranean political scene a bit).
I had this vision of a Hellenistic commander using Byzantine-era field army tactics, with Parthian horse archers replacing Cataphracts. It sounded like a natural progression from the Phalangite-Companion Cavalry combination that Philip and Alexander used to such effect, so I ran with it. And I couldn't help but have a little bit of fun by making the usurper a secret descendent of Alexander, because why not? All these Hellenistic kings go around being proclaimed gods, and nobody ever said "Nah, I'm not a god, I'm just the secret true blood heir to Alexander the Great." Sure, most of the big name dynasties couldn't do that, but there were enough usurpers kicking around in those centuries. I'll leave it to all of you to pick your own personal head canon as to whether Demetrius has it right, or is just bolstering his legitimacy.
