This article is an analysis of events from the death of empress Catherine I to the accession Anna I and the testimonies of the contemporaries close to the throne of the considered period in order to clarify the role of such a document as the testament of Catherine I. The work tries to answer the question: why the most important act for the russian throne-succession was ignored both by the ruling circles and by simple filed in the conditions of the interregnum in January 1730 year.