This book investigates the history of the modern doctrine of account, and by that history, seeks to identify some of the principles and premises which help explain the application of, and which underlie, the action today. The common law account, and its successor in equity, is over 800 years old. There does not appear to have been any work devoted to an examination of that history published in that time. The focus on the book is on the question 'who is an accountable party'? The area of law focused on is common law and equitable remedies, namely, the account (including the subsidiary principle, the 'account of profits').