Hans Karl was educated at the Berlin cadet school, but by the desire of his father, Frederick II's aide-de-camp who had passed into the service of Russia, he also did the same in 1801.

[4] During the next five years of peace, he devoted himself to the study of military science, engaging once more in active service in the War of 1812.

He distinguished himself very greatly in Wittgenstein's campaign, and in particular at Polotsk (18 and 19 October), after which combat, he was raised to the rank of major-general.

[4] In 1815 he attended the Congress of Vienna and was afterwards made adjutant-general to the emperor, with whom, as also with his successor Nicholas, he had great influence.

[4] His greatest exploits were in the Russo-Turkish War of 1828–1829, which, after a period of doubtful contest, was decided by Diebitsch's brilliant campaign of Adrianople; this won him the rank of field-marshal and the victory title of Zabalkansky (meaning "Trans-Balkan") to commemorate his crossing of the Balkans.