A brief description of this important work:
The Celebrated Treatise . . . holds a place in the short list of books that have notably affected the course of history, molding the beliefs and behavior of generations of mankind. Perhaps no other theological work has so consistently retained for four centuries a place on the reading list of studious Christians. . . . The work was designed both as a compendium of the doctrines of the Christian religion and as a confession offered to a persecuting king in behalf of the author’s fellow believers.Institutes of the Christian Religion, Editor’s Introduction, at xxix, xxxiii (John T. McNeill, ed., Ford Lewis Battles, trans., Westminster Press 1960) (1559).
This is perhaps the classic of Protestant theology, and, in addition to basic doctrinal themes, it contains many concise discussions of the law, authority, and civil government.
The preferred edition appears to be the Library of Christian Classics edition: John T. McNeill, ed., Ford Lewis Battles, trans., Westminster Press 1960 (available for purchase here). The 1845 Henry Beveridge translation, published by Eerdmans (1972), is available in paperback, or you can read it online here.