Editing Form of action (section)

==Forms of action==
The substantive law lay buried beneath the various actions: medieval practitioners and judges thought procedurally, not substantively.<ref>See generally [[John Baker (legal historian)|Sir John Baker]], ''An Introduction to English Legal History'' (4th ed); [[S. F. C. Milsom]], ''Historical Foundations of the Common'' Law (2nd ed).</ref> Rights and duties which are today considered to be part of the law of [[English property law|property]], [[English tort law|tort]], [[English contract law|contract]] or [[English unjust enrichment law|unjust enrichment]] were not conceptualised as such.

In the early medieval period, English justice was administered at a local level, first through [[History of Anglo-Saxon England|traditional Anglo-Saxon]] institutions such as the courts of the [[Hundred (county division)|hundreds]] and the wapentakes, and later through the [[manorial court]]s. Following the [[Norman conquest of England]] in the 11th century, a system of centralized royal justice gradually began to take shape. The principal royal courts were King's Bench, Common Pleas, and Exchequer. These royal courts were initially only interested in matters relating to the feudal system: that is, to land law. Accordingly, many of the earliest writs dealt with real property. For example:
* Writ of right
* [[assize of novel disseisin]]
* [[assize of mort d'ancestor]]
* Writ of entry sur [[disseisin]] in the per and cui
* Writ of besaiel
* Writ of [[quare impedit]]
* [[Ejectment]]

Over time, the royal courts began to take notice of other cases. These early writs were in the ''praecipe'' form: they commanded that the defendant perform a certain act or else appear and explain why he had not done so. Examples include the writs of covenant, debt and account. Such writs ''demanded something as of right''.<ref>See [[John Baker (legal historian)|Sir John Baker]], ''An Introduction to English Legal History'' (4th ed)</ref> The royal courts were initially only concerned with ''complaints of wrong'' if the wrong involved a forcible breach of the King's Peace. Such wrongs were enforced by a writ of trespass ''vi et armis contra pacem regis''. During the 14th century the royal courts gradually allowed actions which did not involve breaches of the King's Peace. Instead, the plaintiff would set out his 'special case' in an extra clause, specifying the damage sustained which justified the bringing of an action. This was known as a [[trespass on the case]]. From the trespass on the case developed many other forms of action. Apart from the actions which dealt with real property, other significant forms of action include:
* Action of covenant
* Action of debt ''sur obligation'' ("Debt on an obligation")
* Action of debt ''sur contract'' ("Debt on a contract")
* Action of [[detinue]]
* Action of account
* Trespass ''vi et armis contra pacem regis'' ("Trespass with force and arms against the King's peace")
* Trespass ''sur la case'' ("Trespass on the case" or "action on the case")
** Conversion
** Nuisance
** Negligence
** Deceit
** Action on the case for words (Defamation, Slander) 
** [[Assumpsit]]
*** Special assumpsit
*** Indebitatus assumpsit 
**** [[Money had and received|Action for money had and received to the plaintiff's use]]
**** Action for money paid to the defendant's use
**** [[Quantum meruit]]
**** Quantum valebant

Many actions developed from the action on the case during the later history of the common law. The three most significant of these were:<ref>See generally, Sir John Baker, ''An Introduction to Legal History'' (4th ed); David Ibbetson, ''Historical Introduction to the Law of Obligations'' (2nd ed).</ref> 
* ''The action of assumpsit'', the rapid expansion of which is traced to ''[[Slade's Case]]'' (1602). The medieval law of contract developed in a fractured way through the old actions of covenant, debt and account. In the 1500s litigants began to use the action on the case to enforce contractual agreements (with the exception of contracts under seal, for which debt ''sur obligation'' was required), a shift vindicated in ''Slade's Case''. The modern [[English contract law|law of contract]] then gradually began to take shape.
* ''The action of indebitatus assumpsit''. Following the recognition in ''Slade's Case'' (1602) that assumpsit could be brought in lieu of debt ''sur contract'', a form of action known as indebitatus assumpsit took shape. This action developed several sub-forms known as the common money counts. These actions were initially used to enforce what we would call contractual liability, but they rested on the court implying that a defendant had promised to pay a sum of money to the plaintiff. This promise initially reflected reality, but came to be used fictitiously. Thus where A mistakenly paid money to B, the law would imply a promise by B that B would repay the money: A could then bring an action for money had and received and recover the mistaken payment. The defendant's obligation was not consensually undertaken, but imposed by law. From such actions came the [[Quasi-contract|law of quasi-contract]].  This area of law is now known as the [[English unjust enrichment law|law of unjust enrichment]]. 
* ''The action on the case for negligence'', the rapid expansion of which is traced to ''[[Donoghue v Stevenson]]'' [1932]. The tort of negligence lies at the heart of the modern [[English tort law|law of tort]], which also includes obligations enforced via the old actions of trespass (to the person, to goods, and to land), actions on the case, conversion, deceit, and defamation.