I picked up The Secret History of the Mongol Queens: How the Daughters of Genghis Khan Rescued His Empire by Jack Weatherford a few years ago, on a whim. I don't know a whole lot about Mongolia or Genghis Khan, but I was intrigued that his daughters might have had a hand in saving the empire he built.
The Secret History of the Mongol Queens is split into three parts. The first part was centered around Genghis Khan himself, showing how he built his empire and why his daughters played such an important part in it (he had been betrayed by many men throughout his life, and he needed someone he could trust running things while he took the men off to war). I found this part quite fascinating, especially with just how much power he gave his daughters.
The second part was, in my opinion, the hardest one to get through. This showed how, after his death, the men of his clan undermined and stole power from the women. There are some very dark events covered in this section (I'm not going to lie - a few events I wish I could go back to not knowing about - hopefully they will fade from my memory soon). But there were some really interesting people in this section, like Qaidu Khan and his daughter, Khutulun. Khutulun was a fierce warrior, and she vowed to only marry a man who could beat her at wrestling. While she did end up marrying someone eventually (in the wake of rumours that spread about her and her father having some sort of incestuous relationship), she was undefeated in wrestling!
The final section was about Manduhai and Dayan Khan. Manduhai ended up a queen put in an almost impossible situation after her husband passed away, because whoever married her would become the next Khan. But rather than marrying one of the three obvious contenders, she forged her own path by engaging herself to a child who was the final male heir of Genghis Khan. And rather than using him as most others might have, she ensured that he grew up to be a strong and wise leader, making sure that he was always along when she brought the Mongols to war. Together, the two of them reunited the shattered empire of Genghis Khan for good, while also ensuring that the surrounding countries understood that they had no interest in conquering more territory - the Mongols had learned that it was hard to administer a vast Empire. Though there was about 20 years between them, Manduhai and Dayan Khan stayed together until her death; neither of them took another spouse or tried to depose of the other (although they very easily could have gone their separate ways once Dayan Khan was 18).
While overall The Secret History of the Mongol Queens was an interesting book, I did find the writing to be a bit dry at times. I also thought it would have benefitted from a lot more supplemental material, especially lineages. I found I had a really hard time keeping people straight, particularly in the second section of the book where it moved quite quickly from person to person. This was also the section that did not have any family tree at all when it began.
I'd also like to mention the really neat calligraphy drawings at the beginning of each section. I didn't realize that's what they were until I read the Acknowledgements page - they are by N. Bat-Erdene, and they depict three of the Mongol Queens (Borte, Sorkhokhtani, and Manduhai). According to Weatherford's note, the Mongol people believe the essence of a person survives in the sound of the spoken name and the form of the written one, hence why these drawings are particularly important. He also notes that no portraits of these ladies are known to exist. Very, very interesting!