Along with the Bible, a knowledge of history is intrinsic to the understanding of many of the works of literature and such movements as the Enlightenment, the Transcendental and Romantic movements, Realism, Naturalism, Modernism, etc. Certainly, it is important to place authors in their historical context. Also, do not neglect the study of schism in the Catholic Church with Martin Luther, the Protestant Reformation, and the formation of the Anglican Church in England during the reign of Henry VIII.
Truly, familiarizing oneself with the Greek dramas and poetry is absolutely essential. Also in studying the predecessors of Shakespeare, do not neglect the Anglo-Saxon Epic Poem Beowulf.