This chapter examines the syntax of negative coordination in the history of English. Two major developments can be observed: (a) in Late Middle English it becomes impossible for a negative conjunct clause introduced by the negative conjunction <i>ne</i> to follow an initial affirmative conjunct clause &#8211; since the fourteenth century the initial conjunct must also be negative; (b) <i>nor</i> replaces <i>ne</i> in the second conjunct, which is interpreted as negative but contains no other negative element. These developments follow from two proposed changes in the structure of English clausal negation. First, <i>not</i> replaces a null negative operator in SpecNegP. This operator had checked the uninterpretable feature of <i>ne/nor</i>. Its loss thus requires a c-commanding negative clause to check this feature. Second, <i>nor</i> itself gains an interpretable negative feature, making the following clause negative in interpretation without any further negative element.