This is the first full account of one of the most famous quarrels of the seventeenth century, that between the philosopher Thomas Hobbes (1588-1679) and the Anglican archbishop of Armagh, John Bramhall (1594-1663). This analytical narrative interprets that quarrel within its own immediate and complicated historical circumstances, the Civil Wars (1638-1649) and Interregnum (1649-1660). The personal clash of Hobbes and Bramhall is connected to the broader conflict, disorder, violence, dislocation and exile that characterised those periods. This monograph offers not only the first comprehensive narrative of their hostilities over two decades, but also an illuminating analysis of aspects of their private and public quarrel that have been neglected in previous biographical, historical and philosophical accounts, with special attention devoted to their dispute over political and religious authority. This will be essential reading for scholars of early modern British history, religious history and the history of ideas.