 She entered service in 1847 as a post steamer, operating the route between Stettin and St. Petersburg.During the German revolutions of 1848–1849, the ship was requisitioned by the Prussian Navy for use after the outbreak of the First Schleswig War between the German Confederation and Denmark in March 1848.At the time, the Prussian Navy was effectively powerless to prevent the larger Danish Navy from blockading the German coast; merchant ship owners in various German ports pressured Prussia to arm "Preussischer Adler" and another post steamer, "Königin Elisabeth", but the postmaster general initially refused to turn the vessels over to the navy, since doing so would break international postal treaties.