A man in ornate black armor sits astride a powerful white horse, which rears up dramatically in the foreground. He wears a broad-brimmed black hat adorned with a feather, and his gaze meets the viewer directly, his expression calm and composed. A vivid red sash is tied around his right arm, its ends fluttering behind him, and a red cruciform symbol decorates his cuirass.

His left hand holds the reins, while his right hand is raised, holding a slender staff or baton. The horse’s mane is rendered with energetic, curling brushstrokes, catching the light and contrasting with the deep shadows of the background. Below the horse, a black and white dog runs alongside, its mouth open as if barking or panting, adding movement to the lower edge of the scene.

Behind the rider, leafy branches arch overhead, their forms painted with loose, lively strokes, while the sky opens to swirling clouds and a patch of blue. Light falls from the upper left, illuminating the horse’s muscular chest and the metallic gleam of the armor, while deep shadows envelop the lower half of the scene. Touches of gold on the saddle, stirrups, and the man’s armor add richness to the restrained palette of blacks, whites, and reds.

The brushwork varies from the smooth modeling of flesh and metal to the more textured treatment of the horse’s mane and the dog’s fur. In the upper left corner, a helmet with a plume is partially hidden among the leaves and shadows. The background on the right side features a patch of blue sky with several small birds flying in the distance.

The lower right edge of the painting shows the horse's flowing tail, rendered with long, curling brushstrokes that catch the light. The ground beneath the horse and dog is uneven and painted in dark, earthy tones, with loose, sketchy strokes suggesting rocks or soil. The light striking the horse’s head and chest creates a strong contrast with the deep shadows enveloping the animal’s hindquarters and the dog below. Peter Paul Rubens painted the Equestrian Portrait of Giancarlo Doria between 1606 and 1607.