“It was not until the 1200’s under Pope Innocent II that the church rules changed to only prohibit married priests.”
Married priests are not prohibited.
In fact, there are many married priests right now.
More on the history of married priests. Most Catholics have never heard of this.
“Of the numerous synods convoked throughout Europe during the eleventh and twelfth centuries to enforce with rigour the neglected law, the most notable are the First Lateran Council (1123) and the Second Lateran Council (1139), considered as ecumenical in Roman tradition. Lateran I made into general law the prohibition of cohabiting with wives (c. 7). Lateran II, c. 7, reiterating the declaration of the Council of Pisa (1135), also declared marriages contracted subsequent to ordination to be not only prohibited, but non-existent (... matrimonium non esse censemus). At times, this Council is wrongly interpreted as having introduced for the first time the general law of celibacy, with only unmarried men being admitted to the priesthood. Yet what the Council was doing, in a more pointed way, was re-emphasizing the law of continence (... ut autem lex continentiae et Deo placens munditia in ecciesiasticis personis et sacris personis dilatetur...)60 Subsequent legislation, however, continues to deal with questions relating to married men ordained secundum legem, not contra legem.
The principle sources for this legislation are the Quinque Compilationes Antiquae and the decretals of Gregory IX. These decretals form part of the Corpus Iuris Canonici, a work completed in the fourteenth century and which influenced law-making until the appearance of the 1917 Code of Canon Law. From these sources, we learn that from the time of Alexander III (1159-1181) married men were not, as a rule, allowed to have ecclesiastical benefices; a lower cleric who married would have his benefice withdrawn, but not his right to subdiaconate ordination on the condition that he discontinues his marital life. A son of a priest (considered legitimate if born before ordination) was prohibited from succeeding to his father’s benefice. Young wives and the wives of bishops were to agree at the time of ordination to enter a convent.61 The rights of the wife were also protected.
In 1322 Pope John XXII insisted that no one bound in marriage — even if unconsummated — could be ordained unless there was full knowledge of the requirements of Church law. If the free consent of the wife had not been obtained, the husband, even if already ordained, was to be reunited with his wife, exercise of his ministry being barred.62 One of the factors that must have contributed to the eventual universal practice of ordaining only unmarried men would have been the assumption that a wife would not want to give up her marital rights. Hence the irregularitas ex defectu libertatis of a married man, which became a formal impediment (impedimentum simplex) only in the twentieth century with the promulgation of the Codex Iuris Canonici (1917), was not due to the marriage bond per se. It was due to this assumption of unwillingness and inability to separate. From 1917, all cases of dispensation from the impediment were reserved to the Holy See. But those receiving dispensation were not authorized by that fact to continue with marital relations.63
The decretals and other parts of the Corpus Iuris Canonici provided the guidelines for synodal activity, concubinage being a persistent problem for the authorities. Opposition to the law of the Church was not lacking and occasionally well-respected figures argued for a mitigation of the law to help solve the problems of clerical indiscipline (Panormitanus, at the time of the Council of Basle [1417-1437], for example). The example of the practice of the East was given as a precedent, although it is unlikely that there was a proper understanding of this discipline.64 Similar calls for mitigation were heard at the time of the Reformation. They included humanists such as Erasmus, theologians such as Cajetan de Vio, and secular authorities with pragmatic and political aims in mind: Charles V, Ferdinand I, Maximilian II. The crisis precipitated by the Reformers was doctrinal as well as disciplinary. Zwingli and Martin Luther made the abolition of clerical celibacy a key element to their reform, but this was also related to the dismantling of the traditional theology of the sacramental priesthood.
In the third and final period of the Council of Trent (1562-3), and despite considerable pressures, all suggestions that the Catholic Church should modify and mitigate its rules of celibacy were rejected. In Session XXIV on 11 November 1563, the Fathers upheld the prohibition of clerical marriage (c. 9), adding (concerning the difficulties): «For God would not deny the gift to those who duly ask for it (the gift of chastity), nor allow us to be tempted beyond our strength.» They also rejected the thesis that the marital state should be considered better than that of celibacy (c. l0).65 The Council, in Session XXIII, also voted in favour of founding seminaries to prepare candidates from their youth for the celibate life. The discipline of continence by this time had meant in practice that only an unmarried man would be ordained. This is also shown in the discussions of the Council, for example when one theologian, Desiderius de S. Martino, concerned by the shortage of priests, suggested the possibility of ordaining married men provided the wives gave consent and that they and their husbands lived in continence. But the measure was not deemed expedient.66
The decrees of the Council were not immediately accepted in all nations but with time they did bring about a general observance of the law of celibacy, thanks in no small measure to their provisions for the better training of the clergy. The Enlightenment brought fresh assaults against clerical celibacy and after the First Vatican Council, the Old Catholics, separating themselves from Rome, abolished the rule. Despite the pressures on the Catholic Church to relax the law of celibacy, it has always resisted. Pope Benedict XV declared, in his Consistorial Allocution of 16 December 1920, that the Church considered celibacy to be of such importance that it could never abolish it.67 Following Vatican II, the Church has made an exception for married deacons of mature age and for individual former non-Catholic clergymen, following a precedent set by Pope Pius XII.68”