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Flustered, Ekaterina traced through the family tree in her mind.

Like her grandfather Sergei, the fifth Duke, Vasily, had been granted a marriage to an imperial princess. As was typical for nobles of the Empire, he would have married at around eighteen or nineteen. Portraits of the young Duchess still remained both in the ducal residence in the Imperial Capital and in Jurnova Castle in the duchy.
However, that duchess was supposed to have died young, only a few years later, due to illness. Fortunately, an heir had already been born, and according to the official records, Duke Vasily never remarried and lived the rest of his life as a widower.

But in reality, a few years after his wife’s death, he had encountered a woman he called his companion. Well, formal marriage would have required various procedures, so officially, Giovanna—who went down in history as a male inventor—was never actually his wife. She was likely his companion in spirit rather than by law.
Still, there was no doubt that she was the one woman he had chosen as his only partner.
…Thank goodness. It was not an affair.

Forgive me for doubting you, Duke Vasily. Then again, if your wife had been a nasty old hag, I would have supported you cheating or having an affair with all my heart. But judging from her portrait, she had been a fragile-looking beauty, so she probably was not that kind of person.

That aside… The great historical figure known simply as “the inventor,” Giovanni di Santi… was actually a woman. G-goodness. What a shocking hidden truth of history!
Honestly, as a half-baked history buff, this is delicious. The truth buried in the shadows of history. In my previous life, I was rather fond of theories like “Uesugi Kenshin was actually a woman,” too.

.

“Are you surprised?”

Aurora laughed softly, and Ekaterina came back to herself and nodded.

“Yes, of course.”

Now it made sense. I had wondered why, instead of assigning knights or forest rangers, Duke Vasily had entrusted di Santi’s protection to the forest folk. But if the inventor carried such a secret, then it was understandable. The forest folk, who had no contact with ordinary society and were bound to the ducal house by deep mutual interests, were perfectly suited to assist the inventor while keeping that secret.

Thinking it over again: di Santi’s achievements began when he—no, she—was still in her homeland, by re-establishing the technology for repairing and constructing water and sewage systems that had been lost during the centuries of warfare following the fall of the Astra Empire. She accomplished this while still very young, and Duke Vasily the Fifth, having heard of her fame, eagerly invited her to Jurnova.

When did she start pretending to be a man? When did Duke Vasily learn the truth? Mysteries upon mysteries.

Just then, Aurora handed her an old notebook.

“This is a journal written by the Chief of that time. She was a woman named Lusiola, and she and the inventor were close enough to be called best friends. The contents are fragmentary, but if you read it, you should understand what circumstances led to everything.”
“Thank you very much.”

Amazing. A first-class primary source of unknown history! My excitement is rising.
When she opened it, it began with an exchange like this:

*“I asked her why she pretended to be a man, and why she had fled her country at the risk of her life. She answered, ‘I pretended to be a man to save my father’s life. But if it were known in my country that I was truly a woman, I would surely have been burned at the stake.’”*

Burned at the stake!
And she fled for her life? Disguised as a man to save her father? That is an overwhelming amount of information.

…But yes, there was someone like that in my previous life too. A girl who was burned alive because cross-dressing was considered a crime.
Joan of Arc, the Maid of Orléans.
At least three hundred years ago, the inventor’s homeland must have oppressed women as severely as the medieval Catholic Church.

With the fragmentary notes in the journal, supplemented by Aurora’s and Forli’s explanations, the inventor’s story became mostly clear.

.

Giovanna di Santi was the daughter of a master stonemason in a city near the city-state of Astra.
She was not raised as a boy from the beginning, but as a girl—though not in the least a “girlish” one. From a young age she was a tomboy, running around with the neighborhood boys as her underlings. She had always been clever; merely by watching her older brother Giovanni, who was one year her senior, learn letters from their father, she mastered reading and writing before he did, and he came to resent her deeply.

The city-state of Astra was the former heart of the Astra Empire.
Just as Rome had been the center of the Roman Empire. Rome later became the capital of Italy, but for a long time it too had been only one city-state.
Precisely because of that, the wars after the empire’s collapse were intense. Books were burned, ruins destroyed, and by that time—no, even now, three hundred years later—the major cities did little but fight one another. The culture and civilization that had once flourished had greatly regressed.

Well, in this world it is the accepted theory that warfare caused that cultural regression.
But if large-scale climate changes on a planetary level occurred in this world just as in my previous one, then the fundamental cause of the decline of civilization was probably not war. War was merely one result.
The true root cause was likely the cooling of the climate that continued for centuries from the period of imperial decline.

In my previous life’s research, it is said that from the decline of the Roman Empire through at least the first half of the European Middle Ages, the climate cooled. Crops failed due to cold damage, people starved, northern peoples (the Germanic tribes) abandoned their lands and moved south, conflicts over food and farmland erupted, and the age of war began. There was no longer the capacity to develop or even sustain civilization; the empire fell, antiquity ended, and the so-called “Dark Ages” began.
The same thing probably happened in this world.
Of course, climate change alone was not the only cause, but it must have been a major factor.

In my previous life, an older mainstream theory claimed that medieval culture did not develop much because Christianity strictly suppressed the people.
But Christianity was not strict from the very beginning.
There was a mystery series I quite liked, set in seventh-century Ireland, with a nun as the detective. She was an independent woman who even held the qualification of a lawyer, and marriage was possible for her. The author was apparently a scholar of Celtic studies, so such a situation must have been plausible at the time.
Even in that work, however, Christianity was depicted as gradually becoming more rigid. Later came prohibitions on contact with the opposite sex for clergy, inquisitions, witch hunts, rejection of anything that did not align with scripture—Christianity became increasingly harsh.

Perhaps as the cooling climate reduced people’s material security, they turned more to religion, and that allowed Christianity to seize immense power. Again, not a cause, but a result.

In any case, in this world, where monotheism never became dominant, the broad flow of history still resembles that of my previous life. There were even equivalents of inquisitions and witch hunts, carried out strictly in places such as around the city-state of Astra.
Humanoid monsters—vampires, werewolves, and the like—were deemed evil, and humans who associated with them were branded as fallen sinners.
Romantic relationships with monsters were considered utterly depraved. Even being rumored to have consorted with one could lead to imprisonment and torture, and a confession meant execution by burning.

Before, at the residence in the Imperial Capital, Nonna—the nasty old woman who had served the old hag—had made a fuss about Mina being “tainted.” Now I finally understood why.
Forli had told me that Jurmagna, which had close ties to that old hag, was deeply invested in research on the ancient Astra Empire and also connected to the city-state of Astra. If they were not granted an imperial princess in marriage, they sometimes took wives from noble families of Astra instead. In present-day Astra, people are no longer burned for associating with monsters, but they are still discriminated against. For that reason, Jurmagna does not employ those with monster blood.
Nonna must have absorbed that way of thinking and said those things to Mina, who carries the blood of monsters.

People often call me sheltered. It is probably because I do not know this sort of “common knowledge that cannot be spoken of openly.” I mean, I was confined. How would I know? Not my fault.
And I have no intention whatsoever of being influenced by such thinking in the future! (Clenches fist.)

It is also said that the technology for summoning magical beasts, which once existed in the Astra Empire, was lost because it was deemed an evil practice. Books describing it were apparently burned.

Still, no one really knows when or why monsters and magical beasts came to be labeled evil. In the Astra Empire, controlling magical beasts was commonplace, and even vampires or werewolves could obtain citizenship if they wished (or rather, if they paid taxes).
…Although, a vampire paying taxes is a pretty surreal image.

It was probably because, with climate change, magical beasts grew more powerful and the damage they caused became severe.
There is also a story that during the age of warfare, a particularly powerful monster aided an alien people who came from the north, and after being routed by that monster, the ruler of the city-state of Astra, consumed by resentment, declared that monsters were evil.
Even so, that belief spread not only to the cities around Astra, but even to other countries far away geographically.
It reeks of that unpleasant method of venting frustration by scapegoating minorities in hard times. Holocaust-like, in a sense.

As for Giovanna herself—
She grew up healthy and loved by her father in a small city near the war-torn city-state of Astra, despite all the various forms of oppression.
Her father was a rough stonemason, but also a superb craftsman. He patiently indulged his daughter’s endless “why? why?” questions and taught her everything he could.
In a society where it was said that educating women only brought harm, her father became Giovanna’s greatest supporter and helped her try out her many ideas.

Among those “ideas” was already included the technology for repairing water and sewage systems. While playing in ruined structures, Giovanna came to understand their design. She would tell her father, “I think this used to be like this,” or “If we fix it this way, water should flow again—I want to try it,” and he agreed, and together they experimented through trial and error.
For her, it was all just play. Like summer vacation handicrafts, I think? To unravel ancient wisdom at around the age of an upper-grade elementary school student—geniuses are terrifying. Apparently she failed many times at first, but over several years she gradually established the theory and techniques, and finally succeeded at sixteen.
*Sixteen.* Geniuses are Terrifying.

Her relationship with her brother remained bad. Giovanni, her older brother, had a feminine face and was often mistaken for a girl. Like Giovanna, he took after their mother, and the siblings resembled each other. He lacked the build to become a skilled stonemason like their father, and in academics he could not compete with his sister. He developed an inferiority complex and grew twisted.
Their mother doted on him, and a rift formed between the two pairs: father and daughter, mother and son.

That kind of structure exists everywhere, at any time.

When marriage talks for Giovanna were beginning to arise, war broke out yet again. Their small city was caught up in it, and her mother lost her life to a stray arrow.
Without any time to drive, a storm then struck the family. An Astra noble who commanded the army noticed that water was once again flowing through the repaired aqueduct and demanded to know who had fixed it.
Her father’s name was given. The noble took her father back to Astra with him.