- Thessalonike of Macedon was Alexander the Great’s sister.
- She became queen of Macedon after marrying Cassander, one of Alexander’s generals.
- The city of Thessaloniki in Greece is named after her.
- There is a myth that she became an immortal mermaid after her death.
Thessalonike of Macedon, born in 352 BC, was the daughter of King Philip II and his concubine, Nicesipolis. Her mother’s passing, just 20 days after her birth, left her to be raised by her stepmother Olympias, a Molossian princess from Epirus. Olympias’ union with Philip II was a strategic alliance, intertwining Epirus and Macedon. Thessalonike’s early years, deeply interwoven with her royal heritage, saw her grow alongside monumental figures.
A Political Pillar in Macedon
In the wake of Alexander the Great’s death in 323 BC, Thessalonike’s fate intertwined with Cassander, one of Alexander’s key generals. Their marriage solidified Cassander’s claim to the Macedonian throne. Together, they had three sons: Philip IV, Antipater I, and Alexander V. When Cassander died in 297 BC, Thessalonike found herself guiding her sons through the intricate political labyrinth.
She faced immense trials, notably insisting that her sons, Antipater and Alexander, co-rule Macedon. This decision aimed to ensure her influence as regent through Alexander, sparking resentment in Antipater, who ultimately murdered her. Her assassination mirrored the tragic fates of her sisters, Cynane and Cleopatra, both of whom also met violent ends.

The Mermaid Legend
A captivating legend surrounds Thessalonike. It is said that Alexander sought the Fountain of Immortality, eventually securing a flask of its water. According to the tale, he used this water on his sister’s hair, granting her immortality. Stricken with grief after Alexander’s death, Thessalonike attempted to drown herself but transformed into a mermaid instead. She roamed the seas for centuries, questioning sailors and asking if King Alexander lived. The correct answer, “He lives and reigns and conquers the world,” ensured safe passage. A wrong answer, however, invoked her wrath, leading to doom for the sailors and their vessel.
Thessalonike’s Legacy
Thessalonike’s legacy is preserved through the city bearing her name and the tales enshrining her enduring mystique. Her life, punctuated by her strategic marriage and tragic end, reflects the era’s volatile political landscape. Her transformation into an immortal mermaid remains a testament to her lasting imprint on Greece’s cultural tapestry.
Thessalonike of Macedon is a compelling figure in ancient history. Her life is interlaced with power, tragedy, and myth. From queen to mermaid, her story traverses the annals of history and folklore, immortalizing her in more ways than one.