In the Heldenbuch-Prosa, a medieval German epic, the character Dietrich von Bern faces exile due to a series of events that revolve around his conflicts with other powerful figures and the political dynamics of his time. Here’s a summary of the key events leading to Dietrich's exile:

1. Conflict with Erkinger: The narrative begins with Dietrich's conflict with Erkinger, a powerful nobleman. This conflict escalates when Erkinger, feeling threatened by Dietrich's growing power and influence, seeks to undermine him.

2. The Death of Dietrich's Father: The death of Dietrich's father, King Eberhard, creates a power vacuum and leads to increased tensions among the nobility. Various factions vie for control, and Dietrich finds himself at odds with those who oppose his claim to leadership.

3. The Role of King Gunther: King Gunther of Burgundy plays a significant role in the events leading to Dietrich's exile. Gunther, who is allied with Erkinger, becomes embroiled in the conflict, further complicating the political landscape.

4. The Duel and Betrayal: A pivotal moment occurs when Dietrich is challenged to a duel by Erkinger. Although Dietrich is a skilled warrior, the circumstances surrounding the duel are manipulated, leading to a betrayal that results in Dietrich being forced into exile.

5. The Decision to Leave: Faced with mounting opposition and the threat of violence, Dietrich ultimately decides to leave his homeland. His exile is not just a personal loss but also a significant political event, as it reflects the instability of the region and the shifting allegiances among the nobility.

Throughout the Heldenbuch-Prosa, Dietrich's character is portrayed as noble and honorable, and his exile serves as a catalyst for his later adventures and the quest to reclaim his rightful place. The narrative explores themes of loyalty, honor, and the complexities of power dynamics in medieval society.