Property exists by grace of the law. It is not a fact, but a legal fiction.

What I have in my power, that is my own. So long as I assert myself as holder, I am the proprietor of the thing.

-Both by Max Stirner

Absent a state, enforcement would be an issue. I have a few issues with the AnCap model, and the property rights spook is really one of them.

It seems like it could grow into a pseudo feudal system with large property owners being the kings of "their property" as it would fall to them to enforce their rules themselves, probably by hiring enforcers at the expense of their tenants... You know, because of the terrorists or organized crime or something.

Potentially, a class of property owners could affiliate with each other to establish a ruling class (For lack of a better word, I know that is a loaded phrase.) that controlled a majority of land, they could even partially "sell" the land to others, while maintaining an interest and charging taxes! Kind of like what we have going on now with the state.

It seems all too easy to devolve into a "sign the contract or leave" kind of setup. You owe the land owner 30% of your labor and if you don't like it, go to Somalia.

In the events you mentioned, these autonomous land owners were serving at the pleasure of the crown, so they never actually "owned" their property, the crown did. The tenants were subject to not only these land owners, but also the crown. The Crown is the one with the means to enforce its claim of property.

Anyway I'm a bit conflicted on property rights in ancapistan. I'm sure there would be some benefits to that system, and it might be 100% better than now, but it seems like human nature to dominate his fellow man is a tough egg to crack.

Somehow we have to get to where the individual becomes the only authority that he answers to. Tyranny by informed consent is still a bad idea, though its better than the social contract model many of us currently enjoy.