One of the most important painters of the Düsseldorf School, Oswald Achenbach studied at the Kunstakademie in Düsseldorf. His main influences were his elder brother, the painter Andreas Achenbach (1815-1910), and his teacher, Johann Wilhelm Schirmer. At a very early stage Oswald Achenbach began to prepare studies for landscapes in the area around Düsseldorf, sketching boulders, rocks, bushes, trees and people. From 1843 he went on many study tours, visiting Bavaria in 1843 and northern Italy and Switzerland in 1845. The Bavarian and Italian Alps stimulated him to create a unified approach to landscape painting. In such early works as Landscape (1846; Düsseldorf, Kunstmuseum) his receptiveness to atmospheric values can be seen, even if the precise detail and clear articulation in the foreground, middle ground and background still clearly show his debt to Schirmer.
In 1850 Achenbach travelled to Rome and the Campagna, where he met Arnold Böcklin, who was also studying in Düsseldorf, and Heinrich Dreber. This journey was very significant for Achenbach; from then on Italian landscape and the southern way of life became his main subjects. Numerous drawings and oil sketches bear witness to his intensive study of nature. The warm ochre tones, attention to detail and the severe form of his works at this period still show Schirmer's influence, but after another journey to Italy in 1857, when he visited Rome, Naples and Capri, these traits were almost completely eliminated. In contrast to Schirmer's rational compositional methods, atmospheric elements became crucial to Achenbach's work. His study of light and color had shown him that the best way of conveying the sensation of a plein-air landscape was by blending one area of the picture into the next to create an atmospheric haze of colour, as in Landscape in the Campagna (1855; Düsseldorf, Kunstmuseum). Achenbach's taste for the picturesque and his ability as a colourist enabled him to depict landscapes with conviction and unity. His penchant for using his fingers and palette knife to distribute color and model form was typical of his method of painting, with its broad outlines and wide variety of approaches.
Achenbach achieved international recognition early in his career: in 1852 he was made a member of the Rijksakademie van Beeldende Kunsten in Amsterdam. In 1863 he succeeded Schirmer as professor of landscape painting at the Kunstakademie in Düsseldorf.