He was born in Stockholm. In 1870, he joined the Swedish Navy as a cadet, was promoted to underlöjtnant in 1876 and Commander in 1897.Шаблон:Sfn For 15 years he served on board the royal yacht, Шаблон:Ill; from 1898 he was the commander of the ship.[1]
In parallel to his military career, he was active as a marine painter. He took painting lessons from Шаблон:Ill in Stockholm, but also from Norwegian painter Шаблон:Ill in Paris and Hans Gude in Berlin. He mostly painted marine subjects, including ship portraits and landscapes. In addition to painting, he was also engaged (together with his colleague Jacob Hägg) in promoting the establishment of a maritime museum in Stockholm (which was established after his death).Шаблон:Sfn
His art was appreciated by among others the Swedish king, Oscar II; Herman af Sillén depicted the two together on the deck of Drott in one of his paintings.[1] The German Emperor Wilhelm II and the Queen of Romania also bought paintings by Herman af Sillén. In general he had some international success and exhibited in Berlin, Munich, Washington D.C., and Philadelphia, among other places.Шаблон:Sfn
He married Adèle Anna Viktoria Björklund in 1881. He died in Stockholm in 1908.Шаблон:Sfn