Historical inaccuracies
In the film, Luther refers to Bible passages by the book, chapter, and verse. However, the Bible was not divided into verses until 1551, and even then, the divisions were not ubiquitous until the Geneva Bible. (It can be assumed that this was done so that discerning viewers might easily locate the text to which Luther refers.)
Albert of Mainz is described as being archbishop of two German territories before acquiring Mainz. In reality, he was Prince-Archbishop of Magdeburg and Prince-Bishop of Halberstadt, prior to gaining Mainz.
During the Augsburg Confession scene, all of the nobles, including the prince-electors, stood up to Charles V. In real life, most of the princes were still Catholic. Only one (or maybe two) of the seven electors would have made a stand, Duke of Saxony and the somewhat conciliant Louis V, Elector Palatine. Three other electors were Catholic archbishops, such as Albert of Mainz, and two more secular electors sided with the Catholics, the King of Bohemia, Charles's brother Ferdinand, and Joachim Nestor of Brandenburg, Albert's brother. After the Elector of Saxony and Philip of Hesse, the staunchest opposition came from Georg [the Pious], Prince-Margrave of Brandenburg-Ansbach.
The film stated that Luther and Spalatin went to law school together. In reality, they did not meet until much later.
The film implies that Frederick of Saxony was given the Golden Rose as a bribe to deliver Luther to Rome. In real life, he had already been awarded the rose, most likely to make him run for emperorship against Charles.
Aleander addresses Cajetan as cardinal in his first appearance, which apparently takes place shortly after the papal conclave that elected Leo X in 1513. In reality, Cajetan did not become a cardinal until four years later.
The film regularly portrays congregants seated in pews. In reality, pews were not a common church fixture until after the Reformation.
Leo X is veiled by the cardinals in black mourning garments, when the popes are buried in red liturgical color.
Andreas Karlstadt is depicted as radically distorting Luther's views while Luther is in seclusion at Wartburg, insisting on being addressed as "Brother Andreas." Though the reforms actually orchestrated by Karlstadt were more peaceful, they were too radical for Luther (including vernacularization of the Mass), and Luther began to undo or slow them. Karlstadt also did not renounce his title of professor until after Luther's return.
In the film, Luther returns to visit Wittenberg incognito (at the urging of George Spalatin) with a modest growth of beard and under the title "Knight George." Luther actually had grown a beard "sufficient to deceive his mother" and gone under the name "Junker George," which means "Knight George".
Shortly before Prince Frederick convinces Charles to give Luther a hearing at the Diet of Worms, the Emperor introduces Aleander to him as a "new cardinal", and Aleander's dress supports that. Aleander would in fact not become a cardinal for another 15 years.
It is implied in the film that Luther and Katharina married shortly after the death of Pope Leo X. In reality, Leo died over a year before Luther and Katharina had even met.
At the end of the movie, Luther goes to the study of Duke Frederick with a "birthday gift." He hands the duke a copy of the New Testament in German. There is no historical evidence that Duke Frederick and Martin Luther ever met or spoke face to face.
