The papacy of Pope Clement VII after the Sack of Rome consisted of a large number of crises developing in parallel all over Europe; attempted solutions and reforms put in place prior to the Sack moved too slowly to address the changing situations, and new problems arose faster than the papacy could address them.
In 1524, Pope Clement had sent Cardinal Campeggio to Germany to try to find some solution to the Lutheran problem. He was met with a largely hostile reception, although the Diet of Nuremberg heard him out, and, being asked by him to do so, presented him a list of grievances. They were willing to begin enforcing the Edict of Worms, but they wanted a national council empowered to deal with all matters related to the reform of the Church. Campeggio was, slowly, able to talk them down from this to a German assembly, less than formal council, that would be empowered to do some things, but his hope had been to get them to give up the idea entirely. The Lutherans, on the other side, were vehemently against any such move. The cardinal also investigated problems in the churches throughout Germany, and was given the authority by Clement to enact what reforms he deemed best. Clement had also been able to convince Charles V to insist more vehemently on the enforcement of the Edict of Worms; Charles nonetheless recommended to Clement that he summon a general council, which he suggested could take place at Trent, a relatively minor town that was under Imperial authority but within the sphere of Italian influence. Campeggio was eventually recalled, despite a number of successes, in part because the Curia seemed to be of the opinion that his work had been disappointing, and in part because they seemed to have gotten the impression from other sources of information, despite Campeggio's attempts to disillusion them, that Lutheranism was largely in a state of collapse. In reality, things were getting worse. In 1526, at the Diet of Speyer, the Lutheran princes were able to get the suspension of the Edict of Worms. Germany began to heat up in the aftermath, and things nearly entered a stage of full civil war when Philip, the Landgrave of Hesse, became convinced, on the basis of a forged document, that the Catholic princes had made a league against the Lutheran princes. He hastily formed a counter-league and prepared for war. Fortunately, Martin Luther, who, despite being no friend to the Catholic side, was consistently against any kind of German civil war, and Philip Melanchthon, who saw immediately that there were signs that the document was probably forged, were able to talk the Lutheran league into opening a discussion with their fellow princes, on which they discovered that there was no Catholic league. The problems that arose between the Holy Roman Empire and the Papal States in 1527 exacerbated the tensions.
Meanwhile, a reformation movement was building around Huldrych (often Ulrich) Zwingli in Switzerland. In 1523, he participated in a disputation over reform in Zurich, and was so successful that the city government of Zurich voted to reorganize on Zwinglian principles. Massive changes were implemented over the next several years, as the city seized church properties, made the priests civil servants, implemented a policy allowing priests and religious to marry, and simplified the churches with a policy of iconoclasm. This also set off a chain reaction, as multiple cantons in swift succession followed suit. Some cantons, however, remained opposed to Zwinglian movement; the five alpine cantons (Lucerne, Uri, Schwyz, Unterwalden, and Zug) were especially opposed, and in 1524, as Zwinglianism spread, formed the League of Five Cantons. The difference threatened to split the Swiss Confederation wholly, as the Zwinglian and the anti-Zwinglian cantons each sought foreign allies to shore up their positions. The tensions escalated until in 1529, a Zwinglian pastor was burned at the stake in Schwyz, leading Zurich to declare war and invaded, meeting the army of the League of Five Cantons at Kappel, between Zurich and Zug. The other cantons were able to force a mediation in the Swiss parliament, with the result that the First Kappel War had no battles. The resolution that was developed, however, was satisfactory to neither side, and especially not to the Catholic side. It was inevitable, perhaps, that they would come into conflict again. In 1524-1526, the Three Leagues, which was associated with the Confederation by defense alliance, fought the Musso War with the Duchy of Milan. It had ended with a treaty, but one that had no real force. Milan invaded in 1531, and the Three Leagues called on the cantons of the Old Swiss Confederacy for help. The Three Leagues, however, were Zwinglian, and the Catholic cantons refused to help unless the Three Leagues would repudiate Zwinglianism. In retaliation, Zurich and Bern embargoed the alpine cantons. This led to the Second Kappel War on October 9, 1531. The advantage in this case was sharply in favor of the Catholics, who won; Zwingli died in battle on October 11, and the Second Territorial Peace that ended the war made Catholicism the default, although it allowed most communes that were already Protestant to remain so if they wished. Zwinglianism carried on under the leadership of Heinrich Bullinger, Zwingli's successor in Zurich, but its expansion slowed considerably. Notably almost everything that had been done to block the spread of Zwinglianism had occurred at the levels of canton and town, as Catholic city governments implemented a vigorous reform program and anti-Zwinglianism. The broader Church had almost no influence over the matter, with the result that there was one way in which Protestant and Catholic cantons were very like: the religion was now entirely under the authority of the local governments. In a sense, all of the Swiss cantons had broken from Rome, and none of them considered themselves particularly beholden to the pope; the only difference was whether they voluntarily continued to be Catholic as part of their local traditions or went over to Zwinglianism.
Orvieto had had a long history as a refuge of popes; it was an easily defensible hilltown with a well-built citadel. As Clement arrived in the aftermath of the Sack of Rome, he had practically nothing beyond a small loyal retinue, having to borrow everything from others. He grew emaciated, and his clothes grew tattered, because he could not afford new ones. A few cardinals started trickling in; they were at first the ones who had, for one reason or another, nowhere else to go. And even this was a strain on his resources; Orvieto was a minor provincial town and a great many things had not been maintained properly; they even had to ration drinking water until new wells could be built. As time went on, more trickled into the town, and the Curia was able to begin running again, slowly.
Yet there was one thing Clement still had that was truly beyond all price. He was pope. Even if we consider only the temporal side, the pope, as leader of the Papal States, had played an absolutely crucial role in the balance of European power. It was the most stable Italian power, not large enough to be a major threat to the big players, but significant enough to be able to tip the balance now and then. France and the Holy Roman Empire had grown to rely on the possibility of negotiating papal support for their various projects. Each was more likely to negotiate with the pope than with each other; when they wanted to avoid a particular kind of conflict, the pope was commonly the mediator; politically the pope served as a buffer between empires. With the States of the Church in chaos, there was a gaping hole in European politics that everyone needed to be filled. France and England were practically begging for papal endorsement of their league against the Holy Roman Empire; after the Sack of Rome, such an endorsement would give them a glow of righteousness, whatever they did. Charles needed a papal alliance to restore his reputation as a defender of the faith. Both sides wanted the pope on their side. But Clement was a little bitter over both the Empire's handling of the matter and the rather belated and inadequate support France and England had provided, and a perhaps overly cautious man to begin with, the events of the previous year had made him more cautious still. Clement was reluctant to jump into the fray again. Nonetheless, it should not be doubted that there was steel in Clement's character, and one of his firmest resolutions is that all the cities of the Papal States must be restored to the pope. Slowly things began to settle down in Rome, and, returning to Rome, Pope Clement summoned all the cardinals back. And once there, Clement chose a side and made an alliance with the Emperor, in part because it was clear that several members of the League (particularly Ferrara and Venice) were intent on seizing and holding lands of the Papal States, whereas the Emperor, in the face of the League, could be counted on to back at least a large portion of the papal claims. And, despite having had a number of successes against the League, Charles was indeed willing to make quite considerable concessions if they would stabilize the situation. Nonetheless, something fundamental had changed. The Italian powers, including the Papal States, were now fully within the sphere of authority of the Empire.
In 1529, Suleiman the Magnificent pulled together an army of at least 100,000 men, perhaps as much as three times that, and marched to Vienna. The Ottoman armies were well supplied and well trained, and they had what was at the time perhaps the most advanced artillery division in the world. However, the Ottoman Empire was to face a set of problems that perpetually plagued on its European front, the first of which was that the weather patterns were very different from those which obtained through most of the Ottoman Empire. As the army marched, heavy rains soon nullified its artillery advantage as the massive cannons became stuck in the mud and had to be left behind. Much of the army's camelry also became useless, because the camels were not used to operating in this kind of weather and often became sick and died. And while the logistical system of the Ottoman army was one of the wonders of the world, it was stretched almost to the breaking point in trying to reach Vienna across such difficult terrain. Nonetheless, they had a number of victories on the way, all of which strengthened the Ottoman control of Hungary, and they reached Vienna on September 27. The Viennese had managed to scrape together perhaps 20,000 people, a large number of them peasants and farmers. The Ottoman forces were easily able to lay siege to the city, but their attempts to sap the walls were repeatedly defeated by sorties, and on October 11, heavy rains started falling again. The next day, the sultan called a council, and the decision was made to try one last major assault. (It's very likely, given Suleiman's usual strategy, that he had concluded that he could not take the city, but wanted to severely damage the defenses so as to weaken it for a return in the next few years; but as it happens, he was prevented from completing this plan.) When the final assault was beaten back, the Ottoman forces withdrew. Getting back to Constantinople in the heavy rains was even worse than the march to Vienna had been, but the Austrians were not in any position themselves to press an advantage, and except for sickness and accident, and at the beginning having to fight off a few minor raids, the army had nothing to stand in their way. While it did not have the end he had hoped, the campaign was not a failure for Suleiman -- it brought Hungary much more firmly into Ottoman control, and gave the Empire a better sense of what would be needed to seize Vienna. In Europe, news of the Siege of Vienna led to closer relations between Charles and Clement; to seal this, Clement crowned Charles formally as Holy Roman Emperor the next year.
Also in 1529, another Imperial Diet was held, also at Speyer. This Diet undid everything done by the previous Diet of Speyer. Charles and Clement had agreed to hold a general council, so the Diet prohibited any further innovations for the purposes of reform until it could meet, and it also insisted on the enforcement of the Edict of Worms. In response, the Lutherans entered an appeal, the Letter of Protestation. The Protestation insisted that the Lutheran princes could not in good conscience accept the decision of the second Diet of Speyer; that the decision of the previous Diet of Speyer, which said that every state in the Empire should govern itself in this matter, should be upheld; that papal charges against the Lutherans had been refuted definitively from scripture; that the evangelical Mass (i.e., the Lord's Supper as practiced by the reforming movements) was Biblical; that princes should be allowed to require the evangelical Mass for the purposes of order even if the papal Mass were morally acceptable; that while it would be all very well to insist that Scripture be preached according to the interpretation of the Church, since the disagreement was precisely about what the Church is, the princes should have the right to insist that preaching be according to the text of Scripture alone; that on these grounds they regarded the decree of the second Diet of Speyer on reformation to be null and void, although they would be willing to comply with some of the other decrees, such as the one legislating capital punishment against members of the Anabaptist movement; and that they bound themselves to uphold their Protestation. Thus Protestantism, in the strict and proper sense was born; 'Protestant' became the term for princes, and then followers of princes, who upheld the Protestation of Speyer; it was only later that the term was extended to include other reformation movements (like the Anabaptists).
In the next year, the Imperial Diet was held at Augsburg. For the Diet, the Elector John of Saxony asked Philipp Melanchthon and Johannes Brenz to formulate a statement of Lutheran principles, based largely on Melanchthon's previous attempt (with Martin Luther and Justus Jonas) to formulate such a statement, the Articles of Schwabach. The Protestants attempted to have the statement read in public; the emperor refused, but during the Diet the Saxon representatives read it out loud anyway. The statement, which is now known as the Augsburg Confession, would become one of the key documents Lutheranism. Given both his temperament and the situation, it seems very likely that it was Melanchthon's attempt to insist on Lutheran essentials while being as irenic and generous as possible; as Martin Luther (who was a still an outlaw and therefore not in attendance) is said to have said in mild criticism when he read a draft, it didn't mention purgatorial superstitions and didn't attack the pope as Antichrist. In response, a Catholic commission, heavily guided by Luther's old enemy, Johann Eck, responded with the Confutatio Augustana. The Emperor gave the Lutherans until 1531 to respond. Melancthon would respond the the Apology of the Augsburg Confession, which became an instant bestseller. Meanwhile, Philip of Hesse and John of Saxony, worried that Charles might start responding with force, established a defensive alliance with each other, which would become the Schmalkaldic League.
The Augsburg Confession was not the only Protestant document submitted to the emperor at the Diet of Augsburg. Representing the much more Zwinglian cities of Konstanz (Constance), Lindau, Memmingen, and Strasbourg, Martin Bucer and Wolfgang Capito submitted what became known as the Swabian Confession, or sometimes the Tetrapolitan Confession or the Strasbourg Confession. Cracks had been appearing among the German reformation movements; in 1529, Luther and Zwingli had been unable to come to a common position on the nature and status of the Lord's Supper. The Zwinglians therefore wished to avoid the danger of their views being sidelined. Nonetheless, the Swabian Confession was also intended to be an irenic document, although in this case more to keep open the possibility of union with the Lutherans. It continued to have some influence, and Philip of Hesse and John of Saxony allowed any princes into their alliance who could affirm either the Augsburg Confession or the Swabian Confession.
While all this was going on, Clement and Charles were engaged in an ongoing argument about the best way to move forward with a general council. Charles wanted a full reform council that would also give a full assessment of the Lutheran situation; Clement wanted a council that would primarily be focused on the Turkish threat and on unified action against the Lutherans, believing that the Lutherans had already shown that they would not actually accept any conciliar decision. Charles in the meantime found that the slowly growing Schmalkaldic League was not supportive of action against the Turks, which they did not regard as an immediate priority, which became a significant because in 1532, Suleiman was on the March again. And here we see an unexpected advantage to the Protestants that arose from the fact that the Renaissance reformation, of which Charles was a major supporter, took response to the Turks to be a major item of reform and the Protestant reformation did not: it gave them leverage. At the Diet of Ratisbon, Charles was willing to make concessions in return for support against the Ottoman Empire. The papal representatives vehemently opposed this, but Charles granted the League toleration, and, whatever his precise view of it, Clement seems to have at least understood and accepted this when the news came back to him of it. Meanwhile, Clement's attempts to pull together support for unified action against the Turks were failing, in exactly the ways that attempts of previous popes to do the same had failed. As it happened, Suleiman was stalled at Güns, and so never made it to Vienna. Thus the Renaissance reformation continued to spin its wheels in its attempt to address the Ottoman problem, but the Protestant reformation advanced.
Elswhere, things were also going bad. In 1521, Sweden had broken out into rebellion against the extremely unpopular King Christian II (who at the time was the King of Denmark, Norway, and Sweden under the Kalmar Union). Among the several rebel leaders, one particularly had begun to stand out, Gustav Vasa. Several notable victories massively expanded the rebel army under his command. On June 6, 1523, Gustav Vasa was appointed King of Sweden by the Swedish parliament. A peace treaty was reached with Denmark, now under King Frederik I, in 1524. An incidental byproduct of this was that the archbishop of Uppsala, Gustav Trolle, an important supporter of King Christian, was exiled. Gustav Vasa proposed a candidate for replacing him, Johannes Magnus, to Rome. Clement, however, had regarded the expulsion of Gustav Trolle as illegal, and therefore refused to confirm Johannes Magnus. Gustav Vasa, furious, installed him anyway, and began a process of breaking away from the influence of Rome. In 1527, which is usually as the year that the Swedish Reformation began, the Swedish parliament legislated that the king should have extensive powers over the Swedish church. Given so much power, Gustav Vasa began the Reduction, seizing church property and selling much of it for revenue -- first all episcopal property, then all monastic property, and, much later, parish property. However, Johannes Magnus was a devout Catholic, and was very disturbed at the spread of Lutheranism, particularly given that the new king often lent an ear to the Olaus Petri and his followers. So Gustav Vasa got rid of him by sending him off on a minor diplomatic embassy to Russia and replacing him in the see with Laurentius Petri in 1531. This, along with the ongoing Reduction, led to a rebellion of Catholics against Gustav Vasa, the Third Decarlian Rebellion. The rebellion had some bite, because Gustav Vasa was busy at that time trying to block the attempts of Christian II to retake the throne, but in 1533, this all settled, he offered to negotiate with the rebel leaders. When they came to negotiate, he met them with an army and squashed the rebellion, executing several of the leaders. Meanwhile, Johannes's brother, Olaus Magnus, had gone to Rome to explain the situation, and eventually, in 1533, Clement would conclude that Johannes Magnus was actually a good candidate for the see, and so for the sake of peace, he confirmed Johannes Magnus as the archbishop of Uppsala. However, by this point, it was far too late.
Henry VIII of England had married Catherine of Aragon in 1509; since she was his brother's widow, it required a papal dispensation from Pope Julius II. In 1525, however, Henry began having an affair with Anne Boleyn. Henry, who wanted a male heir that Catherine had not been able to provide, became determined to get an annulment so that he could marry Anne. In 1527, he sent William Knight on a mission to ask Clement for an annulment, on the grounds that Julius's dispensation had been obtained on false pretenses. The mission was a failure, because the Sack of Rome had recently happened, and the pope was still effectively a prisoner in Castel Sant'Angelo; it was extremely difficult even to get in to see him. Given the circumstances -- the pope being effectively a prisoner of Emperor Charles, who was Catherine's nephew -- the king seems to have concluded that the matter was likely hopeless. Thomas Cardinal Wolsey attempted to oblige the king by summoning an ecclesiastical court to decide the matter, but Clement was starting to recover by this point and recalled the papal legate, forbidding any marriage until the matter could be properly addressed. So in November of 1529, Henry summoned Parliament. It began removing legal privileges of clergy and redirecting revenue from the Church to the state, then over the next several years, it went on to reinstating Praemunire (i.e., making it a crime to appeal to any foreign authority against the courts of England) and prohibited any religious appeal to Rome. It also declared Henry's and Catherine's marriage invalid, declaring thereby that Princess Mary, their daughter, was illegitimate, approved Henry's marriage to Anne Boleyn, and required an oath to support their offspring, on pain of treason. As a result, Clement excommunicated Henry on July 11, 1533. As a result, Parliament continued over the next several years to create legislation to undermine papal authority in England, a somewhat complicated matter because England had historically had an unusually close relationship with the papacy.
In 1533, Clement visited France because his cousin's granddaughter, Catherine de Medici, was marrying Henry, the son of Francis I. While there he found much about which to worry with regard to the spread of Lutheranism in France, and issued a bull against French Lutheranism, as well as authorizing the bishop of Paris to begin proceedings against Lutheranism in his diocese. It would have very little effect. In Italy, as well, both Lutheranism and Zwinglianism were spreading, and attempts to deal with this were largely ineffective. Clement, in any case, would have very little that he could do; he was ill for much of 1534, and in June, it took a turn for the worse. He recovered, but relapsed again, and kept doing this until he died on September 25, he died. One of his last acts was to commission Michelangelo to paint The Last Judgment in the Sistine Chapel.
Pope Clement VII is often called the most unfortunate pope, and it is true that he had more than his share of tragedies and catastrophes to endure. The things with which he had to deal while pope had been building for a long time, and there was no way to shunt their momentum aside at an instant. Clement is sometimes criticized for his mistakes, but this is to overlook that the entire political and religious terrain had become so slippery that everyone involved made serious mistakes -- Francis, Charles, Henry, the Protestant reformers, they all made disastrous and nearly disastrous missteps at one point or another. Nobody really understood anything that was happening. And we can see this in the fact that, at the beginning of Clement's reign, there was one major approach to reform -- the standard Renaissance approach, in more papal and more conciliar varieties that nonetheless largely agreed on principles -- battling two minor counter-reformations that seemed to have some serious force, one associated with Saxony and the other with Switzerland. By the end of his papal reign, there were mutually exclusive reformation movements all over Europe, each backed by different political players operating on different principles. The Renaissance consensus about reform had collapsed into chaos. The rivals of the old-fashioned Renaissance reformation backed by the emperor and the pope were multiplying, and they were faster and more adaptable.
Yet the whole terrain was in continual flux, and changes were beginning to take shape that would show that the Renaissance movement for reform, despite its setbacks, had not lost its ingenuity.