Marriage was at the heart of Martin Luther’s break with Rome and the Reformation that followed. He preached sermons praising marriage beginning in 1519 and several years later wrote his first formal treatise attacking the value of vows of celibacy and arguing that marriage was the best Christian life. In 1525 he followed his words by deeds and married a nun who had fled her convent, Katharina von Bora. What started as a marriage of principle and mutual esteem became one of affection and deep emotional bonds. Luther continued to attack the celibate life of Catholic clergy and nuns and to celebrate marriage as a godly estate throughout his career, in sermons, formal treatises, lectures, advice manuals, letters, comments on legal cases, and casual conversation. In all of these, he both praised marriage and family life and commented on its burdensome side, moving from theoretical speculations while he was a celibate monk to reflecting on his own experiences as he became a family man, though his basic theology of marriage did not change much after the early 1520s. His words were direct and blunt, even in formal treatises. Sexual desire was inescapable for all but a handful, he argued, so should be channeled into marriage. Vows of celibacy should be rendered void, and monasteries and convents should be closed or much reduced in size. He agreed with St. Augustine on the three purposes of marriage, in the same order of importance: the procreation of children, the avoidance of sin, and mutual help and companionship. He praised spousal love but asserted that the ideal of reciprocal love in marriage was not an ideal of equality. Proper marital households were hierarchical, for the wife was and had to be the husband’s helpmeet and subordinate. Bearing children was the “precious and godly task” for which women were created, he wrote, and death in childbirth and even the deaths of children were part of God’s plan, though he himself was devastated when his twelve-year-old daughter died. As cities and territories in Germany and then beyond became Protestant, they passed marriage ordinances and established institutions to regulate marriage, turning to Luther for advice on such issues as divorce, desertion, secret engagements, and parental consent. In making their decisions, judges slowly applied the new Protestant ideas about marriage, which people also learned about through sermons, artwork, and pamphlets. In general, however, other than clerical marriage, actual Protestant marriage patterns were not that different from Catholic ones. They fit with secular values as well, for rural and urban residents of all religious persuasions regarded appropriate marriages and stable families as essential to the social order. Recent scholarship has generally rejected earlier views that the Protestant Reformation by itself brought about dramatic change—for good or ill—in marriage and instead noted ways in which the reformers, including Luther, built on ideas and practices that were already there, especially in the middle-class urban milieus in which most of them grew up.