Electorate of Saxony follows Duchy of Saxe-Wittenberg
The Electorate of Saxony, also known as Electoral Saxony  (German: Kurfürstentum Sachsen or Kursachsen), was a territory of the Holy Roman Empire from 1356–1806. It was centered around the cities of Dresden, Leipzig and Chemnitz.
In the Golden Bull of 1356, Emperor Charles IV designated the Duchy of Saxe-Wittenberg an electorate, a territory whose ruler was one of the prince-electors who chose the Holy Roman emperor. After the extinction of the male Saxe-Wittenberg line of the House of Ascania in 1422, the duchy and the electorate passed to the House of Wettin. The electoral privilege was tied only to the Electoral Circle, specifically the territory of the former Duchy of Saxe-Wittenberg.
In the 1485 Treaty of Leipzig, the Wettin noble house was divided between the sons of Elector Frederick II into the Ernestine and Albertine lines, with the electoral district going to the Ernestines. In 1547, when the Ernestine elector John Frederick I was defeated in the Schmalkaldic War, the electoral district and electorship passed to the Albertine line. They remained electors until the dissolution of the Holy Roman Empire in 1806, after which they gained the Saxon kingship through an alliance with Napoleon. The Electorate of Saxony then became the Kingdom of Saxony.
The Electorate of Saxony had a diversified economy and a high level of prosperity, although it suffered major setbacks during and following both the Thirty Years' War of 1618–1648 and the Seven Years' War of 1756–1763. Its middle-class structures were restricted in their development by the nobility and the administration and tended to lag behind contemporary western nations such as the Dutch Republic. Important humanistic and educational impulses came from Saxony through the Reformation that started in the Electorate in the early 1500s. Especially in the 18th century, Saxon culture and arts flourished.
For about 200 years until the end of the 17th century, the Electorate was the second most important territory in the Holy Roman Empire and a key protector of its Protestant principalities. At the time of its greatest extent in 1807 (one year after it was elevated to the status of a kingdom), Saxony had reached a size of 34,994 square kilometers (about 13,500 square miles) and had a population of 2,010,000.Rise of the Albertines as the Protestant protecting power in the Empire
In the Battle of Mühlberg in the Schmalkaldic War, the Albertine duke Maurice of Saxony, an ally of Emperor Charles V, defeated the Ernestine elector John Frederick I (r. 1532–1547). In the Capitulation of Wittenberg, Maurice (r. 1547–1553) was enfeoffed with the electoral privilege in 1547 and with the Duchy of Saxe-Wittenberg in 1548, but contrary to the emperor's promises, he did not receive all of the Ernestine territories.The Ernestine line lost half of its possessions and retained only Weimar, Jena, Saalfeld, Weida, Gotha, Eisenach and Coburg. The fragmentation of the Ernestine possessions into numerous small states began in 1572. Two main Ernestine lines emerged in 1640, the House of Saxe-Weimar and the House of Saxe-Gotha. While the former had only a few collateral lines which were eventually united to form Saxe-Weimar-Eisenach, the House of Saxe-Gotha counted a great many collateral lines, most of which ruled over their own lands.
It was the Albertine territories that for the most part made up what is now Saxony. Once again it became the second most important German state in the Holy Roman Empire after the Habsburg states, with the ability to play a decisive role in imperial politics. The state along the middle course of the Elbe that Electoral Saxony formed was not, however, fully connected geographically. Elector Maurice and his successor, his brother Augustus (r. 1553–1586), worked to fill in the gaps. On 13 July 1547 the estates of the realm from the old and new territories were convened in Leipzig for two weeks as state parliament.
Elector Maurice succeeded in clearing the way for the recognition of the new faith in the Empire. Under his rule, the Electorate of Saxony more than any other power in the Empire protected the Protestant faith. After the conclusion of the 1555 Peace of Augsburg that allowed rulers within the Empire to choose either Lutheranism or Catholicism, Saxony was firmly on the Habsburg side. Augustus, who had replaced Maurice as elector after he was killed in battle in 1553, saw himself as the leader of the Lutheran imperial states in whose interest the status quo achieved between Protestants and Catholics was to be preserved.
The Ernestine duke John Frederick II continued to claim the electoral privilege that had been revoked from his father. When his ally Wilhelm von Grumbach was placed under an imperial ban, John Frederick refused to act against him, and he too was put under ban a year later. Emperor Ferdinand I entrusted Augustus with the execution of the imperial sentences, and his successful military actions against both Grumbach and John Frederick in 1567 consolidated Electoral Saxony's position in the Empire. The Albertine electoral privilege was never again challenged by the Ernestines.