Mehmed II was 21 when he took Constantinople, which is the kind of fact that gets repeated so often it stops registering. Twenty-one. Most 21-year-olds I know are figuring out how to do laundry. He was building cannons specifically sized to crack walls that had held for a thousand years. The walls are worth dwelling on. The Theodosian Walls were the reason Constantinople was Constantinople — three layers, a moat, towers every fifty meters or so, and a track record of shrugging off basically everyone who'd shown up over the previous millennium. The Avars, the Arabs (twice), the Rus, the Bulgarians. The walls held. By 1453 they were old and patched in places and the empire behind them was a husk, but they were still the walls, and there's a reason nobody had managed it yet. Mehmed's approach to this was, depending on how you look at it, either methodical or unhinged. He built a fortress called Rumeli Hisarı upstream on the Bosphorus the year before the siege, basically just to choke off grain shipments coming down from the Black Sea. He commissioned a Hungarian engineer named Orban to cast cannons that were so large they had to be transported by sixty oxen and a crew of two hundred men, and they could only fire seven times a day because they needed to cool down or they'd shatter. When the Byzantines closed off the Golden Horn with a chain across the harbor mouth, Mehmed had something like seventy ships hauled overland, on greased logs, around the back of Galata and dropped them into the harbor from the other side. I want to stress that this actually happened. People reading about it at the time apparently didn't believe it either. You read enough of this stuff and you stop thinking of it as military history and start thinking of it as a personality disorder.
On obsession
I want to skip the part where I compare him to Steve Jobs and Elon Musk. Every essay about driven historical figures eventually ends up there and it's gotten boring, and also it flattens Mehmed into a kind of generic Great Man template when he was, specifically, a 15th-century Ottoman sultan with a deep interest in Greek philosophy and a habit of having his viziers strangled. He's not Elon. He's weirder than Elon. What I do think is worth saying about obsession — and I'm wary of generalizing because I think most generalizations about obsession are wrong or trite — is that it doesn't really feel like wanting something. Wanting has a shape. You want a thing, you get it or you don't, and either way you eventually move on to wanting something else. Obsession is more like a misallocation of your nervous system. The thing you're obsessed with becomes load-bearing. Everything else gets organized around it, including the parts of your life that nobody asked it to organize. Mehmed took the city in May 1453 and then spent the next twenty-eight years on campaign, more or less continuously. Albania, Serbia, the Morea, Trebizond, Wallachia, Bosnia, Karaman, Otranto. He died at 49, on the road, on his way to another war he hadn't finished planning. There is no version of his biography where he sits in the Topkapı palace and enjoys the view. I don't think he would have known what to do with himself.
The entropy part
Here's the thing I actually wanted to write about, and it took me three sections to get to it, which is probably itself a sign that I don't fully have it worked out. Everything decays. This is so banal it's almost embarrassing to say, but it's also genuinely the situation we're in. Walls erode. Empires shrink. Code bitrots. The library you spent ten years assembling gets sold off in boxes after you die. The Theodosian Walls themselves, which Mehmed broke through, were built on top of the older Constantinian walls, which were built because Rome's old walls weren't good enough anymore, and somewhere under all of that is some Greek settlement nobody remembers the name of. It's turtles all the way down, except the turtles are also slowly being ground into sand. What people like Mehmed do, I think, is not actually defeat any of this. Constantinople under the Ottomans was glorious for a while and then wasn't. The empire he built ran for another four and a half centuries and then collapsed in a way that's still creating headlines. Even the cannons rusted. The bombards Orban cast were so impractical that they were mostly abandoned within a generation in favor of smaller, more mobile guns. But something did happen. The city he took became a different city. The trade routes reorganized. A bunch of Greek scholars fled west carrying manuscripts and arguably kicked off the Renaissance, which is the kind of historical claim that's almost certainly oversimplified but not zero. The shape of the world bent, slightly, around the fact of one extremely focused young man and his cannons. Then the world kept going, and bent around other things, and most of what he built is gone or unrecognizable. I don't have a clean ending for this. I started writing it because I was thinking about how much of what I do will outlast me, which is almost certainly nothing, and whether that should bother me more than it does. Mehmed is a useful figure to think with because he's an extreme case — someone who really did push the universe around for a minute — and even his stuff mostly didn't last. If his didn't, mine definitely won't. That's maybe okay. Or maybe it's not. I'm still working it out.