Herman af Sillén grew up in Stockholm with a single mother and four siblings. His mother encouraged his artistic and musical talents from an early age; she herself was very gifted in both fields. In the early 1880s, he took lessons in French watercolour painting from the artist Hulda Schenson. Consequently, Sillén primarily painted in watercolour under Mrs Schenson, but in the autumn of 1887, he had the opportunity to travel to Paris, where he also painted in oil.

The Swedish King Oscar II acquired several of Sillén's paintings, and both the king and the crown prince showed him a kindly interest and made several visits to his studio. The artist also served on King Oscar II's flagship, Drott, and took the opportunity to paint motifs from the Swedish west coast. His name later became known far beyond the borders of his homeland. In Sweden, he received praise for his shimmering colours, excellent atmospheric perspective, and for his unusual ability to express the monumental in the movement of the waves. Sillén was among the first to seriously tackle the depiction of modern armoured ships in oil, which are considerably more challenging to portray compared to sailing vessels.