Well this wasn't on the bingo card. It looks like this series might be all wrapping up skimmed-over plot points.
(BRB, hopefully scribbling "Gelmorran Duskwights", "G tribe" and "Exarch and Lyna" onto the wish list...)
But anyway, this week we get VRANDTINE HISTORY.
So if we count the local calendar in "years after the Flood"...
AF 00 = Flood of Light
AF 02 = first Minfilia born in Voeburt
AF 12 = Ran'jit born
AF 14 = Minfilia discovered and brought to Eulmore - she is 12, Ran'jit is 5
...and here my grand hope of constructing a timeline fades, because we have an unclear gap here.
"After years of secrecy" when she has grown into her role, her existence is revealed and the Sinbound battalion is founded.
Zal'bard is killed/overtaken by the Lightwarden when Ran'jit is "still scarcely more than a boy"
"Ten years after the Sinbound's founding", Minfilia dies in battle.
Three years later her "prophesied reincarnation" is found, but "lasted but a dozen summers, and did not live to see her tenth battle" -- one can only hope most of that time was in training, and she only recently took up the actual fight, assuming she is a direct reincarnation who can only be conceived and born after her predecessor dies. Still, that gives us an estimate of when the first Minfilia might have started fighting too.
If we take age 14 as the time Minfilia was first expected to do battle...
AF 16 = founding of the Sinbound battalion
AF 26 = first Minfilia dies
AF 29 = second Minfilia found
AF 41 = second Minfilia dies
"Minfilia after Minfilia" are born and reborn
AF 80 = Vauthry becomes ruler of Eulmore; Sinbound battalion disbanded.
AF ?? = Vauthry orders the current Minfilia put to death, and tasks Ran'jit with finding and confining her next reincarnation. (?? = 100 - Ryne's age, so around AF 83-84?)
AF 100 = events of Shadowbringers
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So, unfortunately a big thing sticking out to me is, writers can't do maths, or at least don't let things like timelines get in the way of a good story. Everything up to "second Minfilia's" death is fine; events after Vauthry comes in make sense, but that gives us a window of no more than 45 years for all of the other apparently countless Minfilias to live and die. Either they were getting thrown into battle (or, according to this, nobly begging for their own deaths) as literal children, or else there can't possibly have been time for more than three to be raised to young adult age like the first two, even if they didn't survive long on the battlefield after that. Still a cruel number, but they talk about it like there must have been dozens.