Having once set out on the plan of following the _Fasti_, I could not well abandon it, and I still hold it to be the only sound one: especially if, as in this volume, the object is to exhibit the religious side of the native Roman character, without getting entangled to any serious extent in the _colluvies religionum_ of the last age of the Republic and the earlier Empire. The book has thus taken the form of a commentary on the _Fasti_, covering in a compressed form almost all the public worship of the Roman state, and including incidentally here and there certain ceremonies which strictly speaking lay outside that public worship. Compression has been unavoidable; yet it has been impossible to avoid stating and often discussing the conflicting views of eminent scholars; and the result probably is that the book as a whole will not be found very interesting reading. But I hope that British and American students of Roman history and literature, and possibly also anthropologists and historians of religion, may find it useful as a book of reference, or may learn from it where to go for more elaborate investigations. The task has often been an ungrateful one—one indeed of Dipping buckets into empty wells And growing old with drawing nothing up. The more carefully I study any particular festival, the more (at least in many cases) I have been driven into doubt and difficulty both as to reported facts and their interpretation. Had the nature of the series permitted it, I should have wished to print the chief passages quoted from ancient authors in full, as was done by Mr. Farnell in his _Cults of the Greek States_, and so to present to the reader the actual material on which conclusions are rightly or wrongly based. I have only been able to do this where it was indispensable: but I have done my best to verify the correctness of the other references, and have printed in full the entries of the ancient calendars at the head of each section. Professor Gardner, the editor of the series, has helped me by contributing two valuable notes on coins, which will be found at the end of the volume: and I hope he may some day find time to turn his attention more closely to the bearing of numismatic evidence on Roman religious history. It happens, by a curious coincidence, that I am writing this on the last day of the old Roman year; and the lines which Ovid has attached to that day may fitly express my relief on arriving at the end of a very laborious task: Venimus in portum, libro cum mense peracto, Naviget hinc alia iam mihi linter aqua. W. W. F. Oxford: _Feb. 28, 1899_. CONTENTS Introduction 1 Calendar 21 Festivals of March 33 Festivals of April 66 Festivals of May 98