This major new study asks the question, "how much do we know about Shakespeare"s collaborations with other dramatists?", and sets out to provide a detailed evaluation of the claims made for Shakespeare"s co-authorship of Titus Andronicus, Timon of Athens, Pericles, Henry VIII, and The Two Noble Kinsmen. Through an examination of the processes of collaboration and the methods used in authorship studies since the early nineteenth century, Brian Vickers identifies a coherent tradition in attribution work on Shakespeare.