After finishing his studies, he started on a career in government, working as a prosecutor in Mosbach und Mannheim.

[clarification needed] From 1883 to 1890 Marschall von Bieberstein was the envoy of the Grand Duchy of Baden in Berlin, and participated in the fall of Bismarck in 1890.

After Caprivi's dismissal in 1894, Marschall von Bieberstein succeeded him as Foreign Minister of Prussia while remaining State Secretary under the new Chancellor Chlodwig zu Hohenlohe-Schillingsfürst.

Marschall von Bieberstein was increasingly involved in disputes with Wilhelm II, who aspired to have a greater personal influence on foreign policy.

Thanks to Marschall von Bieberstein's efforts, a predominantly German consortium received the concession to build the Baghdad Railway.