Gerard Langbaine's _Momus Triumphans, Or the Plagiaries of the English Stage_ (1687) is significant for a number of reasons. It is, first of all, the most comprehensive catalogue of the English theatre to its time, a list of surprising bibliographical competence and extent for its subject and period and a source study which is still of some use today. Secondly, it serves as the strong and carefully articulated skeleton for Langbaine's elaborately expanded _Account of the English Dramatick Poets_ published some three years later in 1691, and itself a catalogue which remains "a major work of literary scholarship that is immune from obsolescence."[1] Thirdly, and more privately, _Momus_ stands as both a partial record and efficient cause of a quarrel whose claim to our attention is its connection with Dryden. It is a quarrel minor in itself and of which few details are known. Indeed, to call it a quarrel at all is to give a corporeality to Langbaine's adversaries which facts will not directly support, but Langbaine's prejudices against Dryden in _Momus_ and their resulting intensification in the _Account_ suggest a matrix of literature, alliances of taste, politics and religion interestingly characteristic of late seventeenth-century England. _Momus Triumphans_ is based on four prior literary catalogues:[2] [Francis Kirkman,] _A True, perfect and exact Catalogue of all the Comedies, Tragedies, Tragi-Comedies, Pastorals, Masques and Interludes, that were ever yet Printed and Published, till this present year 1671_ (London, 1671); Edward Phillips, _Theatrum Poetarum, Or A Compleat Collection of the Poets, Especially The most-Eminent, of all Ages_ (London, 1675); [Gerard Langbaine,] _An Exact Catalogue of All All the Comedies, Tragedies, Tragi-Comedies, Operas, Masks, Pastorals, and Interludes That were ever yet Printed and Published, till this present year 1680_ (Oxford, 1680); and William Winstanley, _The Lives Of the most Famous English Poets, Or The Honour of Parnassus_ (London, 1687). In his Preface to _Momus_ Langbaine acknowledges his indebtedness to these four earlier lists and asserts "_the general Use of_ Catalogues, _and the esteem they are in at present_" (A2r). But he argues that a new catalogue is needed because the former ones are out of print, "_they were all of them full of gross Errours_," and they are not "_so Methodical as this which I have now made_." Further, he proposes to add "_all the Plays which have been Printed since 1680_" ([A2v]).