In Wikipedia, the first line about Thessalonike says she was 3 or 4 years younger than Alexander, but on the same page, it says when Alexander died, she was 21, which means she was 11 or 12 years younger. And about Cassander, Wikipedia says he was one year younger than Alexander, but in most depiction he seems to be older, and Britannica says he was 2 years older. Same for Perdiccas, Wikipedia says he was born in 355BC, but Britannica say 365BC, other pages mention 360BC. Leonnatus has two dates of birth, 356BC and 358BC.
This makes me wonder are the years of birth of these people really accurate? Wikipedia And I am curious which sources are more reliable.
We don’t have a certain year of birth for any of Alexander’s siblings except Europa, and that only because she was a newborn when Philip died in 336. Every other year of birth is a guess; often a pretty solid one, but a guess. So, we think Kleopatra, his full sister, was born about 1.5-2 years after he was, but it’s not anywhere stated. For all we know, she could have been 3-4 years younger. She was of age to marry in 336, which means only that she would have been born by at least 351/0. In his final two years, Philip married off both of his older daughters: Kynanne to her cousin Amyntas (who, himself, was only in his early 20s, being called an “infant” when his father died in 359), and then Kleopatra.
Do not give any credence to the silly story of Philip being turned off Olympias because he found her sleeping with a snake. The tale was introduced later to provide fodder for Alexander’s “son of a god” status. Olympias no doubt kept snakes for her rites, but Plutarch relates the story in his list of omens surrounding ATG’s birth. In Dancing with the Lion, she’s over 2 years younger than her brother.
We have similar issues with Arrhidaios. He was about Alexader’s age, but we’re unsure whether slightly older or slightly younger. It depends on when Philip married his mother. I chose to make him older in the novel, but only because it served my narrative purposes. In truth, I suspect he was a year or so younger. Kyanne was the eldest, and probably born in 358/57-ish, so even she is only 1-2 years older than Alexander. Remember, Philip married his first 5 wives in his first 5 years of rule (with the possible exception of Nikesepolis, discussed below).
Thessalonike presents a specific problem because her name means “Victory in Thessaly.” That gives us two possible range dates for her birth. The first would have been after 353/2, the victory at Crocus Field and his resettlement of Thessaly into tetrarchies. This is also likely when he married both Thessalian wives: Philina from Larissa (Arrhidaios’s mother) and Nikesepolis from Pherae (Thessalonike’s mother). Yet that doesn’t necessarily mean Thessalonike was born on the heels of a marriage. If she were, her birth year is more likely 351, or late in 352.
The Third Sacred War continued after the Battle of Crocus Field—for quite a few years. Philip imposed a permanent peace on the region in 346/5. So, there’s another possible date for a girl with the name “Victory in Thessaly”: after 345.
In Dancing with the Lion, I went with the earlier date because I wanted all the siblings to be roughly the same age range, to have grown up together. Beth Carney favors the later date, as that was a solid/final victory. The real question is whether Nikesepolis was married at the same time as Philina of Larissa (Arrhidaios’s mother). I think she was, and if I remember right, Beth does as well (and I believe changed her mind). But it’s possible that Nikesepolis was married later, in 346/5, making Thessalonike’s birth no earlier than 344—in which case she would not have known Alexander well (or likely Kleopatra, who was married in 456 and left for Epiros). As stated, I didn’t want that, so I went with the higher chronology.
Whoever wrote the Wikipedia article on Thessalonike cannot, apparently, do math. 353/2 is given as her birth year…which is only 3 years after Alexander’s in 356. Yet the same paragraph says she was born when Alexander was studying with Aristotle, was only 6-7 when he left, and only 21 when he died. Clearly the author confused the two potential birth periods, and failed to notice the dates didn’t match. Also, just to be completely clear, nowhere in the ancient sources is it stated that Olympias raised her, but as she was in Olympias’s party when Kassandros captured them at Pydna, it’s assumed Olympias did. (That assumption goes all the way back to Berve’s early prosopography in the 1920s, Das Alexanderreich auf prosopographischer Grundlage.)
Yet this is the eternal problem with Wikipedia. People get on there and write things when they don’t know the material well, don’t understand the nuances of the problem, don’t cite where they get their information…and apparently can’t even use a calculator.
As for the others you mentioned, Kassandros was younger than Alexander by a few years. Seleukos was about the same age, as were Leonnatos and Perdikkas. But remember, the Greeks didn’t celebrate birthdays, and for many of Alexander’s inner circle, we only have a birth year if they survived ATG and went on to become kings in their own right. But for a number of important figures around Alexander, we must guess at their ages: Krateros, Philotas, Harpalos, Kleitos, Nikanor, Erigyios, Nearchos, etc. We know Parmenion only because we’re told he was 70 when he was murdered by ATG in 330. He was a contemporary of Antipatros, so again, older than Philip by more than a decade. We know Antipatros's age because it's given on the Marmor Parium (an important inscription with an eclectic collection of dates.)
In fiction, we do sometimes play with ages to suit the story. In my author’s note, I explained that I altered several on purpose, to limit the number of names floating about. I could introduce early people who would matter later. So Erigyios, for instance, was not even close to ATG’s age, but probably 20+ years older. I stuck closer to real ages with Ptolemy and Philotas, but even so, we have no birth year for Philotas. We do know the youngest of Parmenion’s sons, Hektor, was younger than Alexander, but enough of a contemporary to be a coeval/attend school with him. We think Philotas was probably about the same age as Alexander’s cousin, Amyntas, something that suited me well in the novel.
(Article mentioned is E. Carney, “The Sisters of Alexander the Great: Royal Relics,” Historia 37.4 (1988): 385-404.)
