The successful military commander and brilliant state administrator became the regent of the newly created Duchy of Saxe-Gotha in 1640 in the middle of the Thirty Years' War. He had the Friedenstein Residential Castle built. He acquired great merits, especially through his church and school reforms. Within a short period of time, Ernst I. established a paternal model state, which served as an example until well into the 18th century. Immediately after his death, he was referred to only as "Ernst the Pious" and was considered a model statesman both at home and abroad.
