The action of detinue stands on the border line between contract and tort. Historically it is an offshoot from the action of debt; in practice it bears a much closer resemblance to tort actions than to these in contract.

The two principal forms of detinue were those upon bailment (sur bailment), and upon trover (sur trover).

The action of detinue, sur bailment, was originally purely one of contract. It could only be used by the bailor against the bailee. The first extension of this right was one permitting it to be used against the legal representative of the bailee after the latter's death. A little later the right was again extended so that where there had once been a bailment, the bailor could bring the action against any one in possession of the goods by alleging that they had come into his hands and possession (ad manus et possessionem devenerunt).

The action of detinue sur trover seems to have arisen in the latter part of the fifteenth century. The allegation in this form of action was that the plaintiff had lost his goods, and that the defendant had found them and refused to deliver them up. At first the losing and finding must be proved as alleged; but later these became mere fictions and detinue became available for any unlawful detention of personal property.

A considerable period elapsed, however, before this action became available against trespassers.

One objection to the use of the action of detinue was that if the defendant surrendered the articles, damages could not be recovered under this form of action for injuries which they might have received. Futhermore detinue, like debt, could be defended against by the wager of law. Largely for these reasons, detinue gave way to trover, as debt did to assumpsit.