Charles's legate, Dr. Matthias Held, alienated the Protestants and stymied all Imperial efforts at settlement.

In response to Held's actions (taken in collusion with Ferdinand, Charles's brother and regent) and to the calling of an ecumenical council by Paul at Trent (in the German-speaking Tirol), the Schmalkaldic League members met in February of 1537 to map their options. The League adopted a new, stronger set of doctrinal statements as the basis of their defensive confederation, which was theologically more removed from Catholicism than the Augsburg Confession. Moreover, they agreed that they would attend an ecumenical council only:

1-- if it were free of Papal control

2-- if Bible was sole authority in any discussion of religious matters

3--if all estates equal

4--if it met on German soil (Trent didn't count)

In the place of grievances that would be normally put before a council, the League asked Luther to draw up an authoritative set up theological principles: the League then demanded the acceptance of these principles without qualification:

a--justification by faith

b--abolition of the Mass (sacrifice)

c--monastic revenues were to be used for schools and charities

d--denial of divine mandate of Pope to rule the church.

When the Schmalkaldic League threatened war, Charles finally got word of what was going on in the north. He fired Held and appointed the archbishop Lund to make peace. Peace was maintained with a new truce, the Treaty of Frankfurt in April 1539. Then Charles tried to solve the religious crisis with a series of conferences involving arbitration between Lutherans and Catholics. In this attempt he received considerable encouragement from certain Italian high church people. Gasparo Contarini was the most significant of these persons. In 1540 and 1541, three such conferences were held: Hagenau, Worms and Regensburg (most important). An agreement of sorts came out of the latter, known as the Book of Regensburg. The Lord's Supper question remained the most divisive issue, however.

About this time, the fourth Hapsburg-Valois War started up, in some ways much as the last one had, on the sea as well as the land. This time Charles fleet was destroyed by a storm before the port of Tangiers in October of 1541. In the East, the Turk had been called in by the counter claimants to Ferdinand as ruler of Hungary; namely, the supporters of John Zapolya, since the latter's death in 1540, they claimed the throne for his infant son, John Sigismund. The Turk moved and took Buda, in Hungary, and once again threatened Austria and the Empire. Charles sent an army to stop the Turks, but it utterly failed and it was really bad for Charles in the east.

In the west, Francis had finally concluded a formidable alliance against Charles concomitant to the task. This new alliance included Turkey, Cleves, Sweden, Denmark, and Scotland. Moreover, it engaged the Pope as a hostile, though non-fighting force, against the emperor.

At the same time, Hesse and Saxony attacked the Duchy of Brunswick and they seized the duke's lands because he was supporting the emperor. Almost simultaneously, Archbishop Albrecht of Mainz allowed Protestants into his lands and Herman von Wied, Archbishop of Köln, invited Martin Bucer and Philip Melanchthon to introduce Protestantism there. In 1543, moreover, the principality of Waldeck and the great town of Münster became Protestant. Things were looking really bad for Charles.

It is apparent that things looked grim for Charles. But, due to Philip's bigamy and the consequent loss of authority, Charles was able to ally with Henry VIII and grab the Gelderland. Philip agreed not to resist Charles in return for the Emperor's promise that he would not prosecute him for bigamy. Charles then, in 1543, made peace with the Protestants with a promise at the Diet of Speyer in 1544 that there would be a national council called. Hence, by taking Gelderland Charles strengthened his position in the western part of the empire and stopped the spread of Protestantism in the west by isolating the aggressive Protestant leader, there, Duke William of Cleves. He ended the war by the treaty of Crépý.

Now Charles was finally ready to solve the religious schism. He declared the elector John Frederick of Saxony and Philip of Hesse banned for the Pack Conspiracy of 1528, the war for Württemberg in 1534, and the seizure of Brunswick in 1545. He got away with this for two reasons. First, the members of the Schmaldaldic League had been demoralized by the bigamy of their leader and he no longer commanded the respect and authority that he had once enjoyed. Second, he finally had some Protestants in his camp; he convinced them that religion was not the real issue. Duke Maurice of Ducal Saxony aided the emperor although a staunch Lutheran by attacking Electoral Saxony and dividing Schmalkalic forces--he wanted the electoral title. Charles now enjoyed a victory over Saxony at Mühlberg, in April 1547, and captured the elector. Philip of Hesse was talked into surrendering without a fight by his Son-in-Law, Maurice,who promised him he would help his case and who assured him that the Emperor had promised that the punishment would be light. Both men were then imprisoned in the Netherlands for five years.

But Charles still couldn't settle the Luther matter or bring the wars to a successful conclusion. Now squabbling with the pope, Charles tried to bring a religious compromise to the Empire, known as the Augsburg Interim. This interim arrangement was imposed at the Diet of Augsburg, in June 1548, and was supposed to represent a German compromise until an ecumenical council could settle the matter definitively. It didn't work.

What happened next? France, now under Henry II, joined with Maurice of Saxony, who had what he wanted and now needed to get his father-in-law, Philip, out of jail. Maurice brought the Landgrave William of Hesse, son and regent for Philip during his captivity, and Margrave Albert Alicibiades of Brandenburg into the alliance. They attacked Charles in the War of Liberation. It ended in Peace of Passau (1552). After one last vain attempt to regain Metz from the French, Charles gave up.

The final peace between the estates was written up later, in 1555, and is known as the Peace of Augsburg. These are the important points:

1--Lutheran princes, imperial knights, and imperial towns were guaranteed security equal to that of Roman Catholics and both were obligated to maintain "eternal, unconditional peace"

2--each estate (principality, knight, or town) will choose the religion: cuius regio, eius religio. Subjects who do not like it may move to another place that hosts their religion.

3--all church lands seized before Passau (1552) will remain Protestant--all bishops and ecclesiastics turning Protestant after Passau will forfeit their titles and lands. As my mentor, Harold J. Grimm, put it, the princes agreed to disagree in religious matters, in order to secure their princely liberties.

It should also be noted that the issues disputed and fought over by France, Spain and the Empire were finally settled with the Peace of Cateau-Cambrésis and the Peace of the Pyrénées in 1559. This 1559 treaty set the boundaries between the West European countries for decades to come. Until the Thirty Years War, their was peace.
Poor Charles retired from his emperorship in 1556. He divided his inheritance and empire between his son, Philip, and his brother Ferdinand. Philip got the Low Lands and Castile-Aragon. Ferdiand got the Empire and Austria.