Andreas Achenbach (1815–1910) was a German landscape and seascape painter born in Kassel. He began his studies in Düsseldorf in 1827. Achenbach worked in the Romantic style and is considered a founder of the Düsseldorf School. His brother, Oswald Achenbach, was also a landscape painter.
Achenbach's oeuvre contributed significantly to the international reputation of the Düsseldorf School. He specialized in landscapes and seascapes, employing a Romantic aesthetic. Together with his brother Oswald, they were known as the "Alpha and Omega" of landscape painters, a reference to their shared initials.
