Solothurn and Biel have recently joined together to form a city theater alliance. The two theater commissions appointed opera singer Leo Delsen as the new director, reported the Bieler Tagblatt on April 26, 1927, without much enthusiasm. And although it was viewed with a considerable amount of skepticism, this marked the beginning of a cultural collaboration between the two cities that continues to this day, finding a common path for their theater despite significant differences. The authors of this publication recount part of this history, along with many individual stories that took place there over time. The contributions create a comprehensive panorama that describes the diversity and uniqueness of this theater within the Swiss theater landscape. A documentation section listing the productions and their directors since 1972 complements the work.