The preparation of an English text of the Liber Pontificalis, of which the following pages furnish the first installment, is something more than the translation of a crabbed text, crowded with obscure references. Even of the great libraries in this country only about ten possess the original in the best working edition, if one may judge by library returns, and it is doubtful if many more copies of the complete text exist this side of the Atlantic. A document which long was viewed as of fundamental importance for the history of the Papacy has thus sunk so completely out of sight as to have become a rather rare curiosity to all but research students of medieval history.