We report here on the set of complete proofs of Volumes I and II of Whitehead and Russell’s Principia Mathematica newly acquired by the Bertrand Russell Archives. These proof sheets, marked with a number of corrections, were likely bound for Russell by Cambridge University Press, though not exactly the same as the first edition. We assess the information to be gained from the texts and the corrections, most significantly around *110 in Vol. II and the lost dot of the empty relation in Vol. I. All are in Russell’s hand and described in an appendix. We also note several revisions in the first edition that were made after these proofs. We discuss the provenance of the volumes, and Russell’s correspondence about proofs of PM with M. H. Dziewicki, but we find that there is insufficient evidence to determine the chain of possession from Russell to their discovery for sale in Australia in recent years.