Baltzar Julius Ernst von Platen (1804–1875) was a Swedish noble, naval officer, politician and diplomat.

[2] Being the son of navy officer Baltzar Bogislaus von Platen he was born 16 April 1804 in Frugården in Skaraborg County.

[1] At a young age he learned the basics of seamanship by serving several years on a Swedish merchant vessel.

After his return to home in 1825, he was employed as aide to his father and then at the office of the general adjutant of the Swedish Navy.

However, his plans were met with the continued resistance, and the problems associated with procurement of equipment in an era of many naval inventions and quick developments led him to resign again in June 1868.

When king Charles XV died and was succeeded by Oscar II on the throne in 1872, von Platen knew that the new king disagreed with his naval reforms of 1866 and that the Archipelago Artillery would soon be abolished which indeed happened in 1873. von Platen, therefore, resigned in December 1872.