The Chiliarch had soon conceived the notion of heading west and securing the eastern Mediterranean seaboard from Egypt to Macedon. While later writers would romanticize the project, conjuring up sentimental images of the grieving Chiliarch seeking solace in the icy embrace of the queen mother
Olympias,
Hephaestion’s motivations were indubitably political first and foremost. Far-flung Macedon was still the putative heart of the Empire: the regent
Antipater's authority in Greece had grown obnoxiously strong even for Alexander, how much more so for mere Hephaestion. Alexander’s sisters and nieces were also a liability: any enterprising adventurer could annex any one of them, obtaining a claim to the Regency and throne and providing Hephaestion’s enemies with a figure to rally around. Unrest and dissension had broken out upon Alexander’s death, and while circumstances - namely, the royal pregnancies - had kept Hephaestion some months in Babylon, the birth of the royal prince and princess had left him free to set out for whichever province required attention.
More importantly, however, the birth of the royal prince had compelled Hephaestion to reevaluate the security of his own position as Chiliarch and
prostates (guardian) of the King. The baby boy’s mere existence was sufficient for any mediocre oratorian to whip up the army into a dangerous frenzy - the boy’s mother sufficiently nubile to ally herself with such a man and wield him, together with her father and the other satraps of the East, with enough force to shatter Hephaestion’s regency and drive him and his out of Persia altogether. It was not a threat to be taken lightly - certainly not one he could coexist with for any length of time. Roxana had grown accustomed to power; no sooner had she borne her babe than she set about seeking a suitable match for herself with one of Alexander's generals.
The solution readily presented itself: forestalling any potential rivals, Hephaestion wed Roxana himself, thus securing the unwavering loyalty of her Sogdian and Bactrian kin and the undisputed right to her infant son. Roxana was thus rendered harmless and deprived of any aid she might have expected from her father or his people.
It was simultaneously expedient to bolster Arrhidaios' legitimacy as King: Hephaestion gave him the throne name
Philip and united him in marriage with
Stateira II, sister of Hephaestion's first wife and another widow of Alexander. Arrhidaios’ idiocy bestowed his consort with far greater power than was customarily inherent to the position - Stateira was loyal to Hephaestion and grateful for a marriage that assured her comfort, security and preeminence. As Stateira's closest male kinsman, Hephaestion obtained a double claim to the Regency. Now no one could attempt to usurp power by manoeuvring some pliable wench into Arrhidaios' side; nor could anyone deny the Regency to the step-father of the royal heir. Shortly afterward Hephaestion also took
Barsine into his household, securing the guardianship of her child and seeking thus the good will of her powerful relations in Asia Minor; as a precautionary measure the remaining widow of Alexander,
Parysatis II, kept her place at court and was also nominally united to Arrhidaios.
Thinking his own position now secured, Hephaestion set about organizing the latest recruits from Persia and preparing for the coming march. If at all possible he hoped to show up in Europe unexpected and unopposed, to set both Olympias and Antipater under his thumb and settle affairs as seemed best to him. Several pretexts presented themselves for his westward progress - the intended conquest of Cappadocia and Paphlagonia, or otherwise of Carthage; even the burial of Alexander in the traditional resting place of the Argead kings, should the Chiliarch venture so far as to contravene the late King’s expressed desire to be buried at his divine father Ammon’s oracle at Siwa in the desert. Events were soon to overtake these preparations however.
Reaction to the Babylon weddings was far more negative than Hephaestion had anticipated. Neither Antipater nor Olympias were pleased. The same officers who had insisted he take the throne now chaffed at his brazen and untoward usurpation of
basileia. Some among the Macedonian host took to sarcastically calling him
Eutychus ("fortunate"), a biting commentary on how he had seemingly profited from the death of his former beloved.
His detractors in Babylon were led by the capable and ambitious
Craterus, an older and more experienced general whose unwavering loyalty to Alexander had seen the late King dub him
Philobasileus ("friend of the King" or "the King-loving"). While Hephaestion had been simultaneously nicknamed
Philalexandros ("friend of Alexander" or "the Alexander-loving"), Craterus maintained his own individual claim to a special bond of trust with Alexander. Indeed, he had originally been chosen by Alexander to replace Antipater as the ruler of Greece, Macedon and Thrace; it was only his ill health that had resulted in the nomination of
Seleucus to the office. Craterus opted to understand this substitution as a temporary state of affairs - Hephaestion's confirmation of Antipater's rule was, to him, nothing more than a direct offense on his person and honour.
Craterus therefore lead the charge of Alexander's generals and officers who encumbered Hephaestion daily with supplications for a redistribution of satrapies amongst them. They were sour that Hephaestion had advanced several Orientals, all the while keeping them in the tedious and rather humiliating service of the idiot Arrhidaios. They expressed their outrage by hounding
Histanes, brother of Roxana, whom Hephaestion had promoted to a position of command over the elite Persian units, and demanding the execution of
Ochus, the young son of Darius whom Alexander had seen fit to spare[1]. Histanes for his part did little to meliorate the situation - emboldened by his sister's marriage and his nephew's birth, he went to great pains in order to ingratiate himself with Hephaestion, hoping that once the latter inevitably seized the throne he might have the Chiliarchy himself. His efforts paid off when Hephaestion named him satrap of Babylonia and charged him with the planned reconstruction of the Esagila temple complex.
Things reached boiling point when a drunken Histanes publicly accused
Iollas and
Cassander, the sons of Antipater, as well as
Medius (the lover of Iollas and the man at whose banquet Alexander had fallen fatally ill) of poisoning the late King. Hephaestion dismissed the accusations as drunken words spoken late into a banquet and Histanes suffered no punishment. When Craterus' demands for punishment were not met, the army erupted into a great clamour - some baying for the blood of Iollas and Cassander, others for that of Histanes.
[1] According to Curtius a grandson of Sisygambis outlived Alexander long enough to try (unsuccessfully) to console her upon Alexander's death.