An entail is a legal device that has a narrow form and a broad form. Many people mix the narrow and the broad form. The narrow form of entail-which persists from generation to generation (until something like 1926, when it was converted into an equitable interest-but that's well outside the scope of our time period)-is a legal fiction that deals with the way that land is given.

Let's take back a step. Land is given. Who's giving? Jump back to feudal times. Land was usually given from lord to tenant, in exchange for some service. The service might be the provision of armed men, or giving up thirty cabbages in fall, or something ridiculous like jumping over a stream or delivering a flower. As you can imagine, land under this sort of an exchange wasn't alienable; you wouldn't want the beefy man with four sons to give up his land to the weedy dude with only daughters is military service was what you got from giving the man the land.

This system, of course, had long eroded by the time the Regency period came into play. But the bones of the system were still in play: at bottom, the state owned reversion rights to the land (that's why people talk about estates going to Prinny if there's no heir), and so if there was no heir, the state became the successor.

So what does it mean to be an heir? Now we start getting into places in which I often see errors. First, it is simply not true that under the law of primogeniture, the eldest son always inherited the property. That was the default rule-if the father died without a will, the eldest son got everything. But in the upper classes, the father almost certainly made a will, and he was perfectly capable of giving land to younger sons. In fact, a very famous case-the Duke of Norfolk's case, from the late 1600s, dealt with complications that arose when the Duke of Norfolk arranged his will to give land to his second and third sons.

So you could will land to people besides the eldest son. You could even will it to daughters. Wives. Younger sons. Cousins. Favorite servants. Nothing stopped you.

Nothing? Well, not quite nothing. There were two things that could stop you. First, the property might have transfers restricted. Second--and this seems obvious now, but it's really important--you can only give away things that actually belong to you.

The entail, in the strict sense, is a restriction upon transfer. When the land was originally granted to the first owner, it was often granted with conditions. Those conditions might look like this: "To A, and the heirs of his body." Or "To A, and his heirs." Or "To A, and the male heirs of his body." Or even, if you had a very poor lawyer, "To A, and his male heirs."

So what do those conditions mean? If land was granted to A and the heirs of his body, it was entailed. Technically, it was granted in fee tail, which means that only children of your body could inherit it. Children? Which children? Well-whoever the heir was. That heir could be female; nothing in the condition of transfer prevented it. If land was granted to A and the male heirs of his body, it could only go to male heirs. And of course, in the paternalistic society of the time, much of the land that was granted in fee tail, as it was called, was granted in fee tail male.

It was only by practice, rather than operation of law, most properties were entailed upon the male line.

By the time the Regency period rolled around, there was no property that was truly encumbered by this sort of entail. They'd developed a legal fiction called the common recovery. The basic idea was quite simple. A friend would sue for your property. You wouldn't object. They'd take the property-and they'd take it in fee simple, namely, without the entail attached. Then your friend would give it back to you. This method was very well-established by the Georgian era. And so the mere fact that a property was placed in fee tail mail could not have stopped someone with enough time (it might take a year or two) or money (it would cost at least a few hundred pounds) from undoing the conditions.

But today, we use the word "entail" to encompass more than property that was restricted from transfer because it was granted in fee tail. The broad meaning of entail, by the Regency period, was not a condition placed upon the transfer of property; it was a condition placed upon the ownership of the property. That might not make much sense, so let me give an example. Imagine I have an estate, and I want to pass to my son, and to his sons. But how do I prevent my hapless son from squandering everything? That's easy. I don't give my son the whole estate. I give him what's known as a life estate--meaning, I only give him ownership of the property while he's alive. Then I give the remainder--that would be the property that's left over, namely, the estate after my son has died--to his eldest son. My son's only allowed to spend what he has. If he wants to rent his estate for life and live in Brighton, he's free to do that. The only thing he can't do is sell anything on his estate for longer than the duration of his life. And that's about all I can do: entail the estate on the next generation.

Why? Why can't I just give my son the estate for life, and then when he dies, HIS sons the estate for life, and then when they die, THEIR sons the estate for life? Well. Now we come back to the Duke of Norfolk's case, and the Rule Against Perpetuities. The Rule Against Perpetuities says, in layman's terms: You can't boss people around that far into the future.

More specifically (and this is not quite right, sorry, but there's details I'm leaving out), it says that a condition is invalid if it is possible for the condition to still be in force when everyone alive at the time of the grant is dead plus twenty-one years. And so you couldn't apply the condition to your unborn grandson. In order to make the entail while you're alive, you (a) grant yourself a life estate; (b) grant the remainder for life to your eldest living male heir; (c) grant the remainder to the eldest of his living male heirs.

That violates the rule against perpetuities. How? Imagine you are the patriarch. You grant yourself an estate for life, remainder for life to your eldest male heir. Then all your sons up and die. Luckily, you remarry, and you father a son. At the time the grant was made, this son was not alive. You die; your son inherits.

Your son lives for a very long time. He lives until everyone alive when the bequest was made is gone. He lives for thirty years after that. Thus, 21 years after all lives in being have terminated, the condition that passes the estate to his eldest male heir is still in force. Is this likely? No. Is this probable? No. Did courts at the time care? No. In fact, in the case of Jee v. Audley, a court in 1787 held a somewhat similar condition invalid, on the grounds that 80-year-old parents might have had another child. Not only was it impossible for the 80-year-olds to reproduce because they were, well, 80, but at the point when the court decided the case, they were dead. Did that matter? Not one bit.

One last comment about Pride & Prejudice. The entail that's discussed in Pride and Prejudice is not a fee tail male; it's a life estate granted to Mr. Bennett, with the remainder given to his next male heir. In Mr. Bennett's case that male heir happened to be Mr. Collins. You can actually tell this by the text. When describing the entail, Jane Austen explains: "This son was to join in cutting off the entail, as soon as he should be of age, and the widow and younger children would by that means be provided for." Here's how that would work: Mr. Bennett has a life estate. His son would have the remainder, for life. If you put together their two halves of the estate-- present and future--they together own the whole estate. All they would have to do was have one of them grant their half to the other, and they could then parcel it out as they wished.