This dissertation studies the manuscript transmission of the Latin speech delivered by Cicero in defence of the actor Roscius in a legal dispute at Rome in the first century BC. It considers the authorship and circulation of the speech in the ancient world before turning to the only source of its text today, the manuscript Vaticanus latinus 11458 in the Vatican Library. Watermark evidence and contemporary records are used to confirm that this copy of Pro Roscio comoedo was made by Poggio Bracciolini in Cologne cathedral in 1417. A recent claim that there are other independent witnesses to the text is, sadly, refuted. The script, spelling, abbreviations, numerals, layout, corrections, annotations and paratextual material in the Vatican manuscript are investigated, as well as its earliest copies, to cast light on the process of transmission. Special study is made of the editorial terminology in Poggio’s annotations. A synoptic picture of how this Latin text was transmitted from ancient Rome to the Renaissance is presented in conclusion.
