In this 1965 text, Dr Moore divides the extant manuscripts of Polybius, the Greek historian of Rome who lived in the second century BC, into their families, and demonstrates their relationship to each other. He considers the three traditions separately, and in each he describes the manuscripts briefly and discusses any part of their history which can help in establishing their relationship. He then establishes the tradition, discussing the manuscripts in their families and considering each one in its place in the establishment of the tradition. In his opening chapter he deals with previous editions of Polybius, and he concludes with a a chapter discussing the relationship between the three groups of manuscripts, the Archetype, and possible reasons why the text should have survived in the form in which it has. This was the first study to take account of all the surviving manuscripts.