In time and place, Da Vinci's Demons is closest to The Borgias - in fact, in the exact same places in Italy, and only two decades or so years earlier. You'll find familiar family names - such as the De Medici's and the Sforza's - as young Da Vinci (25 years old) contends from Florence with the Pope and his nephew. The lovemaking and nudity is also in good supply - even a bit more with Da Vinci, as befits his Renaissance-man talents as a painter and anatomist - and the ambience is as lush and captivating.
But Da Vinci's Demons has far more than political and erotic intrigue. Da Vinci was a scientist and inventor far ahead of his time - sketching helicopters and tanks that could well have been built right then and there had the needed collateral technology been at hand. Like Heron of Alexandria 1400 years before him and Charles Babbage 400 years later, Da Vinci belonged to the very small group of visionaries who literally saw the future in their fundamental understanding of the world around them. Indeed, Da Vinci is easily at the top of this class, and his scientific pursuits, which included not only anatomy but botany and geology, are amply portrayed in the series. Da Vinci's Demons in its scientific story lines is akin to Vikings on the History Channel, and its excellent depiction of Norse advances in ship building - though the Viking science of ship building is one-dimensional in comparison to what Leonardo wrought.
Such extraordinary range and depth of real scientific knowledge logically spills over into science fiction and fantasy, or speculation about what deep wells of knowledge are feeding this world, and reside beyond. The possibility that the ancients knew far more than we give them credit for has long been a theme in my own science fiction, and figures in such popular culture triumphs as The Da Vinci Code and Rimbaldi in Alias. Da Vinci's Demons features an ancient (fictional) Book of Leaves, which contains knowledge of the universe that goes well beyond science. As the young Leonardo begins to learn of this book and its secrets, he comes into conflict with the Vatican and its desire to contain it and keep it from the world. As is the case with all good science fiction, there is a proximity to reality which gives it punch: Leonardo comes across a map of a continent which no one recognizes but he somehow knows is true. It's a map of South America, a few decades before Columbus, a time when other historically unrecorded voyagers could well have made the trip across the Atlantic, as the Vikings in fact had done some 500 years earlier.
Da Vinci's Demons thus has everything a devotee of historical fiction and science fiction could ask for. In its fantasy elements, the series also has a kinship with Game of Thrones, but the situation of Da Vinci's Demons in our real world makes it more compelling in my book.