In On Campaign, the viewer is greeted with a vibrant palette dominated by earthy tones and bursts of color. The painting depicts soldiers in a dynamic setting, suggesting movement and action. Figures are rendered with a sense of urgency, their postures conveying the intensity of their mission.

The background features a landscape that enhances the narrative of the campaign, filled with rolling hills and a dramatic sky. The painting is executed in oil on canvas, a medium that allows for rich color depth and texture. Rusiñol's brushwork is expressive, with visible strokes that add to the dynamism of the scene. The composition is balanced, drawing the viewer's eye across the canvas from the foreground to the background.

The approximate dimensions of the work are 100 x 150 cm, making it a significant piece that commands attention. Santiago Rusiñol was a prominent figure in the Catalan Modernism movement, known for his vibrant use of color and light. On Campaign reflects his interest in historical themes, often depicting scenes of social and political significance. An interesting fact about this work is that it was created during a period when Rusiñol was deeply engaged with the cultural and political issues of Spain, making it a reflection of his times.