This chapter tells the history of legal fictions from the emergence of the common law in the twelfth century until the abolition of the forms of action in 1852. It begins with an overview of the procedural framework which allowed, and encouraged, fictions. It then considers eleven old fictions: (i) dominus remisit curiam; (ii) vi et armis; (iii) geographical fictions; (iv) bill of Middlesex; (v) the writ of quominus; (vi) benefit of clergy; (vii) pleading the belly; (viii) common recovery; (ix) trover; (x) ejectment; and (xi) quasi-contract. For each fiction, I identify the reason for its existence, its development, its manner of operation and its effect on the law. Importantly, the fictions are classified in a way which explains their survival or extinction. This Effect Classification distinguishes between Jurisdictional, Auxiliary and Essential Fictions. The Effect Classification plays a central role in the Acceptance Test, which is the thesis of the book.