Recently I bought very nice Leopold I 5 Francs 1851.
His Wiki portrait looked like one of portraits of Russian Heroes of Napoleonic wars.
His Wiki biography is very interesting.
In 1795, as a mere child, Leopold was appointed colonel of the Izmaylovsky Guards Regiment in Russia. Seven years later, he became a major general. When Napoleonic troops occupied the Duchy of Saxe-Coburg in 1806 Leopold went to Paris. Emperor Napoléon I offered him the position of adjutant, but he refused. Instead, he took up a military career in the Imperial Russian Cavalry. He campaigned against Napoléon and distinguished himself at the Battle of Kulm at the head of his cuirassier division. He received Golden sword for his bravery at Leipzig. In 1815, at the age of 25, Leopold reached the rank of lieutenant general in the Imperial Russian Army.
He became King Leopold I of Belgium in 1831.
Some generals deserve to become kings.