Countess Juliane took up government, together with Count Johann Ludwig, Reichsgraf von Wallmoden-Gimborn as regent for her minor son George William.

Immediately afterwards, Landgrave William of Hesse-Kassel occupied Schaumburg-Lippe militarily, arguing it was a fief of Hesse, and vacant after Philip II's death.

With support from Hanover, Prussia and the Imperial Council, Juliane managed to achieve a rapid withdrawal of the Hessian troops.

She conducted thorough reforms of the economy and education, downsized the court, continued the tolerant policy towards the Jews her father-in-law had introduced and managed to cut taxes.

She appointed Bernhard Christoph Faust as her personal physician, and helped him significantly with the introduction of the smallpox inoculation.