Her father was King Cleomenes. Cleomenes was once visited by a dodgy foreigner called Aristagoras, who proposed Sparta join in a very dubious project. After Cleomenes refused, this is what happened:
Aristagoras followed Cleomenes with an olive branch in his hand, like a suppliant, and besought Cleomenes to listen and send away his only child, Gorgo, a little girl of 8 or 9, who happened to be standing by her father's side. Cleomenes told Aristogoras to say what he wished and not to mind the child.The proposal the 8 year old Gorgo had just advised her father against was a Spartan invasion of Persia. High politics indeed, and Gorgo was listening in, and learning, from a very young age.
Aristagoras began with an offer of 10 talents, to be paid to Cleomenes if he consented. Cleomenes shook his head, and Aristagoras gradually increased his offer. When he went as high as 50 talents, the little girl exclaimed, "Father, you had better go away, or the stranger will corrupt you." Cleomenes appreciated his daughter's warning.
There seems to be a tradition by the way of Spartan Kings playing with their kids while conducting affairs of state. For remorseless killers they were pretty good family men.
Gorgo was the only child of Cleomenes. Because of this, when he died (in very odd circumstances, but I'll leave that for another post), Gorgo was in the extremely unusual position of being the female heir to a Spartan throne. She inherited because she was already married, to a chap called Leonidas. Leonidas became King.
Yes, that Leonidas, the one who would later lead the 300 at Thermopylae. Leonidas was in fact Gorgo's father's half-brother, making this obviously a dynastic marriage, yet by all accounts it was also a very happy one. Gorgo became a one-woman brains trust backing the Spartan leadership, and Leonidas became the second king in a row to take her advice.
There was living in Susa at the time Xerxes decided to attack Greece, an exiled Spartan called Demaratus. Demaratus wanted to send a warning to the Spartans, but knew any message sent by him would be read (no doubt by the Eyes and Ears of the King). So Demaratus scraped all the wax off a wax tablet (which is what people back then used to send letters) and scratched his warning into the backing board of the tablet. Then he reapplied the wax and sent an apparently blank tablet to Sparta.
The Spartans were totally confused when a blank tablet arrived from Persia, sent by a man they'd exiled. No one had any idea what it meant, until they took it to Queen Gorgo, who by this time had a thorough reputation for being the smartest person in Sparta.
Gorgo looked at it, deduced there was a message beneath the wax, and had it scraped off, and thus the Greeks had warning of the coming war and time to mobilise. The Spartans sent word to Athens, where Themistocles had spent the last 10 years preparing for this moment, and his plan went into action. (It's certain that Themistocles and Gorgo met and spoke after the war, and that must have been one fascinating conversation.)
Gorgo knew perfectly well, when Leonidas led the mission to Thermopylae, that her husband wouldn't be coming back. She famously asked him what she should do, and he replied, "Marry well and bear children, and live a good life."
It's not known if she followed the advice, but she'd already borne Leonidas a son, Pleistarchus, who assumed the kingship when he came of age. With Leonidas and Gorgo for parents it must have been a tough act to follow, but he did a reasonable job.
Gorgo totally bought into the Spartan ethic. She was once asked by an (obviously frustrated) woman from Attica why the Spartan women were the only ones who could rule men. Gorgo replied, "Because we are the only ones who give birth to real men."
Gorgo is one of the very few women mentioned by name in the Greek histories, and one of even fewer to have had direct influence in politics. The only woman to compare with her in the Classical age is Aspasia, who followed in the next generation.