Edit: The English scanlation is up and running again! I am doing proofreading and typesetting. I can't link it because when I tried it was taken down for promoting illicit copyrighted content.
Cesare: the Destroyer Creator is about the political child prodigy Cesare Borgia (pronounced Chess-ar-ay Bor-ja, by the way), along with his stoic but skeptical right-hand man Miguel and the innocent but intelligent peasant-born Angelo. Cesare navigates the corrupt, difficult world of the Catholic Church as he strives for his father to become the next pope. Born illegitimately, he cannot technically become a cardinal himself but makes every attempt to establish himself as a valuable member of the Holy See. But in the midst of Italian in-fighting, religious conflict, and the discrimination of his Spanish heritage, this is no small task. It also explores the infamous Medici and Borgia families.
This manga is incredibly underrated. Compared to every other historical manga I have read, it is by far the most well-researched. I can't vouch for its historical accuracy as I have not done much research myself on Cesare Borgia, but it comes across like it knows what it's talking about. It's not a light read, not at all. It's info-heavy and extremely detailed. Most other historical manga will modernize the story just a bit to make it more digestible, but not Cesare. It reads like it was written in the time period it's based in. It helps if you know a bit about Italian/Catholic history and geography first, which I didn't, so I must admit some parts can be confusing and you might have to reread to absorb everything. For this reason it was honestly quite hard to read for me, but the characters and art carried it in my opinion.
But nevertheless, it deserves much more praise, especially from the historical seinen community. I can tell that some might be turned away by the art style as it's very yaoi/shojo-like (since that was what the mangaka did before I think) however it does not read like that at all. (There's way more old men than pretty boys lol)
The art is simply incredible as well. It captures Rennaisance Italy as if the mangaka was able to time travel and draw from life.
Cesare is a multifaceted, morally gray character in the likes of Griffith, but in his case, his character is based on an actual person. He is a manipulator and takes advantage of the corruption to advance his own agenda. However, in many cases, he is actually the most morally sound person in the room. It's quite an interesting dynamic.
Angelo exists as a sort-of narrator, he observes Cesare's antics from a more unbiased perspective and starkly contrasts Cesare. Miguel appears to blindly serve Cesare, but over time it is revealed he is in fact his own person, he can see right through Cesare's manipulation and recognizes he's hard to truly understand, but he lacks the confidence to express his conflicting ideas.
At times, it seems like it's about to go in a strange, romantic direction, there's sometimes a lot of tension between Cesare and Miguel or even with his sister, but it never strays from its political-driven plot. In this way I feel it's most realistic, perhaps it's just a cultural difference from today, I wouldn't know, but I strangely appreciate it.
Be warned, from what I can tell, not all of Cesare is translated into English (only up to volume 9 iirc, 79 chapters) and it seems that the scanlation team has no intention of continuing as their website is gone and I can't find any more information. I've also had trouble finding out if the manga was canceled or if the mangaka is still slowly publishing because the English speaking fanbase is so small that almost nothing about it exists online. It's a shame, honestly.
I have a hard time pitching it to people, as a story about corruption in the Catholic church probably does not seem very interesting for most people, but the intricacy of the philosophy, politics, and psychological battles are on par or even better than those of Berserk, Vagabond, Vinland Saga etc.
If you are interested in history and religion and perhaps politics as well, I could not recommend Cesare more. It's complicated with many moving parts, but at the same time, it's a beautiful look into the power-hungry side of the Catholic church.