See H. C. Lea, The Dead Hand (1900); C. Zollman, American Civil Church Law (1917).
During the Middle Ages in countries such as England the church acquired a substantial amount of real estate. As the church and religious orders were recognised as a legal person separate from the office holder who administered the church land (such as the abbot or the bishop) then the land would not go to the king on the death of the holder, as the church and the religious orders would not die. This was in contrast to feudal practice where the nobility would hold land on grant from the king in return for service, especially service in war. This meant that the church over time gained a large share of land in many feudal states and so was a cause of increasing tension between the church and the Crown.
In 1279 and again 1290 Statutes of Mortmain were passed by King Edward I to circumscribe the church's holding of property, although limits on the church's power to hold land are also found in earlier statutes, including the Magna Carta of 1215 and the Provisions of Westminster of 1259. The broad effect of these provisions was that the authorisation of the Crown was needed before the land could vest perpetually in a corporation.
Although statutes prohibiting mortmain have been abolished in most countries today, the principle still subsists to a certain extent in relation to trust law in the form of the rule against perpetuities.
Mortmain played an important part in legal history, and earlier case law often needs to be considered against this background. For example, the judicial decision in Thornton v Howe held that a trust for publishing the writings of Joanna Southcott was charitable being for the "advancement of religion." This decision is often held up as setting the bar extremely low in determining whether a charity is for the advancement of religion, but if one considers that at the time the statutes against mortmain were in force, and that the effect of the decision was that the trust was void, rather than imbuing it with special privileges in relation to taxation, it puts a very different spin on the ratio decidendi.