Godly Republicanism is about the republican civil and church governments created in Massachusetts in the early 1630s and about the fear of tyrannical power that in large measure shaped them. Familiarity makes it easy to forget how extremely bold and ambitious a project Massachusetts was. The colony's royal charter, it was generally argued, gave the colony virtual independence from the English government, to the point where Massachusetts was being called a "free state" (republic) by the end of the 1630s. In this quasi-republic, innovative churches, virtually independent of each other, in which the laity enjoyed a great deal of power, worked hand in hand with a civic government whose leaders voluntarily made themselves completely accountable to the people. Churches and state were tied together by an unprecedented franchise based not on property but on membership in the increasingly exclusive churches. Leaders and people alike vigilantly watched against any signs of incipient hereditary rule. Recent historians have taken for granted the secularism of early English republicanism. That republicanism, they argue, was the product of a pristine relationship with ancient classical treatises, unmediated by the intense religious conflicts rocking England and driving puritans to America. Contemporaries knew better. Massachusetts' defenders extolled their quasi-republic as the culmination of radical puritan reforming efforts stretching back to the Elizabethan presbyterians. Those presbyterians had sought to eliminate what they regarded as the popish, antichristian tyranny still remaining in the recently Protestantized Church of England. Among other reforms, they would replace the monarchical and unaccountable rule of the bishops with wide distribution of power and accountability to the people. Comparisons of presbyterian churches to civic republics were common in this period. Although presbyterians swore their faithfulness to the English monarchy, monarchs feared them out of a conviction that their republican churches would inevitably lead to the downfall of monarchy. Godly Republicanism traces puritans' consequent growing disillusionment with their sovereigns. Antichrist, from their perspective, was growing increasingly successful in his unceasing efforts to pull the Church of England back towards Catholicism. England's monarchs themselves were increasingly coming under the power of his agents and were growing more tyrannical as they did so. By the end of the sixteenth century, the struggle against Antichrist's tyranny in the church was becoming a struggle to resist his corrosive effects on the English state. That twin struggle grew even grimmer in the early seventeenth century. The radicalized puritans who settled Massachusetts were veterans of fierce, unsuccessful political fights against what they saw as King Charles I's accelerated descent into tyranny and toward Catholicism (while Charles saw himself as battling covert republicans). Those emigrants did not leave England with clear blueprints for church and state. Contemporary sources agree that the separatist congregational church at the hard scrabble, tiny Plymouth Plantation, founded in 1620, was the most significant influence on their churches. The settlers' profound disillusionment with monarchy, their royal charter's latent legal possibilities, and their novel participatory churches all made it possible for them to conceive of a new totalizing form of republicanism. That republicanism was built on a dynamic synergy between their republican state and republican churches, linked by the colony's unprecedented approximation between the body politic and the body of Christ, the members admitted to the colony's strict, increasingly exclusive churches. As the colonists felt their way into their creation, they, or at least some of the most inspired ideologues among them, discovered in it profound possibilities for resolving political problems of decay and corruption with which republicans had long been concerned, in church and state alike. This discovery was facilitated by the fledgling polity's increasing viability in the mid-1630s, a viability that confirmed its institutions' divine mandate. With this confirmation came a new understanding of what the colony signified. It had become a critical part of God's scenario for the end of time. It was a city on a hill, to use the biblical phrase, its churches were fit for the world's emulation, and a few prominent puritans in England were starting to agree. A migration that started as flight from England's anticipated divine destruction found itself, through trial and error, unexpectedly opening a new chapter in sacred history. While Massachusetts settlers were discovering what they understood to be the unprecedented efficacy of their biblically perfected republican church/state establishment, the English religious and political conflicts that had driven them to emigrate continued to escalate. In 1642, a puritan-led parliament took up arms against King Charles I. Eighteen chaotic, intermittently republican years of puritan rule followed in England. Scholars have conventionally dated from this period what has been called the "Atlantic Republican tradition" that culminated in the American Revolution. However, the founders of that tradition, they have insisted, were no puritans; they were anti-Calvinist, proto-Englightenment figures. Godly Republicanism closes with a close examination of one of those founders, an icon of the eighteenth-century "Age of Revolution," Algernon Sidney (1623-1683). It shows that puritan republicanism left an indelible imprint on his thinking. The long stream of Atlantic republicanism had as one of its headwaters the puritan struggles that created Massachusetts.