Michael Servetus (c.1506-1553), denounced by many of his contemporaries as an arch-heretic and celebrated by others as a martyr for the cause of religious freedom, escaped from imprisonment by the Inquisition, but was convicted of blasphemy by the Swiss Protestants and executed by being burned at the stake. The sequence of events leading to Servetus's death began with his publication of a theological work he had long been composing in secret, The Restoration of Christianity. This work contained, among other things, a critique of Trinitarian orthodoxy and advocacy of adult baptism. This book, the first volume of a projected series, contains translations of books 1 and 2 of Restoration, focusing on his critique of the Trinity and his interpretation of key passages from the Bible. Included, for purposes of comparison, are a portion of his early theological treatise On the Errors of the Trinity (1531), a sample of the marginal notes and chapter headings that he provided for the second edition of Santes Pagnini's translation of the Bible (1542), and an early draft of the opening pages of Restoration. An introductory essay orients the reader to this complex work with discussions of what is known (and not known) of Servetus's life; the structure of Errors and Restoration; Servetus's approach to the study of the Bible; his interest in Islam; his theology, and its relationship to several well-known Christian heresies; the identity of the people whose ideas he wished to correct; and what his ideas may offer to today's readers. In addition, more than 200 annotations guide the reader through difficult passages and provide additional background information.