This thesis examines the performances which have earned Sir lan McKellen a reputation as one of the foremost Shakespearean actors of the day. His reputation has been built on five major performances: Richard II, Macbeth, Coriolanus, lago and Richard III. His performances as Hamlet, Romeo, Leontes and Kent were only limited successes. This thesis places McKellen's performances in these roles in the specific context of the production as a whole. Where it is relevant it assesses the significance of the casting of other roles, the influence of the personality, style and interests of the director, the policy of the theatre company and the impact of the performance space. This thesis identifies patterns in McKellen's work determined by his own personality and sexuality, the Cambridge education he shares with Sir Peter Hall, John Barton and Trevor Nunn, and his relationships with other actors. The Introduction considers the characteristics of a McKellen Shakespeare performance and assesses the importance of his intellectual approach to the text. It looks at how his sexuality has influenced his performances. His devotion to touring is also highlighted. Chapter 1 concentrates on the Shakespeare roles McKellen played early on in his career. Chapter 2 is devoted to McKellen's celebrated performance as Richard II. Chapter 3 examines McKellen's interpretation of Hamlet. Chapter 4 looks at his performance as Edgar in the Actors' Company's King Lear and his taking over the role of The Bastard in the Royal Shakespeare Company's King John. Chapter 5 considers his performance as Romeo and chapter 6 his interpretation of Leontes. The success of McKellen's portrayal of Macbeth is scrutinised in Chapter 7, and his Sir Toby Belch in a touring production is also examined. Chapter 8 assesses the strengths and weaknesses of his performance as Coriolanus at the National Theatre. His NCO lago is explored in Chapter 9. Chapter 10 looks at the difficulties McKellen confronted when playing Kent and Chapter 11 the success of his portrayal of Richard III.