How did Lutheranism develop?

Lutheranism simplified religious ceremonies, abolished icons, relics, and crosses, allowed priests to marry, worshiped in local languages, and practiced cheap churches. The Lutheran church was headed by vassals and was not controlled by the pope. There was no unified Lutheran Church in Germany because the lords were not subordinate to each other. The lords of northern and northeastern Germany, such as Saxony, Mecklenburg, Prussia, and Brunswick, converted to Lutheranism and took advantage of the opportunity to seize the property of the Catholic Church. The lords in the south and southwest were mostly Catholic. The division of Germany continued, but the Peace of Augsburg in 1555 stipulated the principle of "religion follows the state", i.e. the lords had the right to decide on the faith of their subjects. Lutheranism was legalized. In the sixteenth century, Sweden, Denmark and Norway also converted to Lutheranism and established Lutheran churches subordinate to the king's authority, thus breaking the monopoly of the Catholic Church. Today, Lutheranism is the largest of the Protestant churches, and is very powerful in Germany, the United States and the Nordic countries, with about 70 million believers.