New Historicism is a literary theory based on the idea that literature should be studied and intrepreted within the context of both the history of the author and the history of the critic. Based on the literary criticism of Stephen Greenblatt and influenced by the philosophy of Michel Foucault, New Historicism acknowledges not only that a work of literature is influenced by its author's times and circumstances, but that the critic's response to that work is also influenced by his environment, beliefs, and prejudices.
A New Historicist looks at literature in a wider historical context, examining both how the writer's times affected the work and how the work reflects the writer's times, in turn recognizing that current cultural contexts color that critic's conclusions.