First published in 1973. This is the second edition and nine years after when The Age of Marshall was first published. The period 1890-1915 in the history of British Economic Thought may aptly be described as the Age of Marshall. His influence as teacher, and his ideas as presented in the Principles of Economics (1890) and other writings, stimulated and often dominated the ideas and writings of most of the younger economists of the period. His ideas also provided a theoretical basis for increasing state intervention in economic life of the community in Britain and thus helped the Liberal Government of Great Britain lay the foundations of a Welfare State.