At this point things get a little weird.  Kyaxares’s son Astyages becomes king of the Medes.  He has no son, but instead a daughter named Mandane, about whom he dreamed a dreadfully prophetic dream.  In the dream, Mandane peed and the pee flooded the capital and then flooded all Media and then all of Asia!  I said it gets weird.  Astyages was thus extremely reluctant to allow Mandane to marry and have children, in case the children should turn out to be horrible pee-elementals who would rampage across the world.  However he couldn’t stop her from marrying forever, so he turned her over to a nice quiet Persian who wouldn’t make any trouble, Cambyses.

After Mandane married Cambyses, Astyages had another bad dream.  In this one, Mandane gave birth to kudzu, which soon covered all of Asia.  Astyages thought this a pretty bad sign, and when Mandane and Cambyses’s son Cyrus was born, he ordered his cousin and chief henchman, Harpagos, to steal his grandson and kill it and bury it somewhere.

“Seems like a terrible idea to me,” said Harpagos.  “But you’re the boss, boss.”

Cut to Harpagos and his wife sitting down for dinner, with little Baby Cyrus in a baby-caddy on the kitchen table.

“I can’t help but notice you’re sobbing,” Harpagos’s wife said.  “Is something the matter?”

“This is just a shitty situation.”  Harpagos puts his head in his hands.  “Astyages ordered me to murder his grandson, but he doesn’t have a son and so this baby is his heir and also I’m his cousin and I’d be next in line for the throne if not for this baby and if I murder the baby then it’s going to come out eventually and people will be like, he can’t be king, he murdered the heir!”

“Hmm.”  Harpagos’s wife considered.  “That does sound shitty.”

Rather than kill Baby Cyrus, Harpagos and his wife decided to mail him out to the boonies.  They sent him to a slave-shepherd they knew, Mitradates, and his slave-wife, whose name Herodotus is very apologetic to say is Spaca, because she was a slave and somebody thought that was funny.  And yes, “Spaca” translates to an extremely derogatory name for a woman which was just as offensive twenty-five hundred years ago as it is now, but Herodotus is trying to give it to us straight.

Harpagos turned Baby Cyrus over to Mitradates without explaining that he was the heir.  “King Astyages commands you to murder this baby,” he told Mitradates.  “If anybody comes along and this baby is alive, then you’ll be punished!  Don’t think you won’t!”

Mitradates took Baby Cyrus away to Spaca, who, Herodotus didn’t mention this before but it’s about to become plot-relevant, she was barren and had just miscarried and also she really wanted a baby.  (Maybe you can see where this is going.)  “Check it out,” Mitradates told Spaca.  “I was given this baby and told to murder it, but I’m not sure if I should, since it’s the heir.”

“It’s the heir?”

“Yeah, you can tell because it’s dressed in finery and also because back in town everybody’s talking about how the heir was stolen and is presumed dead.  And Harpagos, who gave me this baby, told me that Astyages demanded it be murdered.  So, yeah.  Putting two and two together, it’s pretty plainly the heir.”

Spaca of course fell in love with Baby Cyrus immediately.  “We are not murdering this baby!”  She got an idea, which she cajoled Mitradates into carrying out, which involved swapping her recently-miscarried dead fetus for Baby Cyrus, and telling people that Mitradates had killed the heir as ordered, and Spaca raising Baby Cyrus as their own.  “The dead child will obtain a royal burial and the surviving one will not lose his life,” she said.  “It’s a compelling argument!”

So that happened, says Herodotus.  No way was all this made up after the fact to justify the son of two slaves (one of whom was given the worst name) later becoming ruler of the Persian Empire.