Through considerable detective work, this work sets out to show that Julius Caeser was the first play performed at the new Globe Theatre on 12 June 1599. Drawing on many areas of expertise, which are rarely allied in Shakespeare scholarship to such an extent, including biblical, liturgical, social and theatrical history, the author sheds new light not only on Julius Caeser but on a variety of accepted beliefs. These include: why Hamlet was not crowned king when his father died; why Brutus would not swear to murder Caeser; why the Elizabethan authorities retained the Julian calender; and why the orthodox dates of the first composition of both Twelfth Night and Hamlet can be called into question.