This book is a centenary volume to mark 100 years of Cambridge English exams. The volume chronicles the history of Cambridge ESOL, from the first administration of The Certificate of Proficiency of English in 1913, up to the present. It covers intertwining themes such as mission, exam range, constructs, content, theory and practice, research and validation, and also explores relationships with key countries, institutions, centres, staff and test-takers. Printed in full colour with an attractive layout, the volume includes many photographs and unique access to archival material and interviews with key stakeholders.