The portrait in part gains its impact by its directness and sense of contained power: the horse's strength seems just in check, and Charles' brilliantly shining armour and the painting's deep reds are reminders of battle and heroism.

[3] The emperor was very aware of the importance of portraiture in determining how he was seen by others, and appreciated not only Titian's mastery as a painter, but also the artist's manner of presenting him as a ruler.

He had developed such a strong friendship with Charles by the time of this portrait that the emperor's courtiers were uneasy at the extent that a lowly painter was allowed into his confidence.

Titian described imperial Augsburg as the glory of the world and told his friend Lorenzo Lotto that he was surrounded by all the favours of the court and of the Emperor.

[11] Drawing on sources such as Roman military art (the statue of Marcus Aurelius on horseback), Renaissance equestrian imagery such as the engravings of Hans Burgkmair, and possibly Dürer's 1513 engraving Knight, Death and the Devil,[1] Titian departs from the traditional rendering of rider on horse, in which one of the horse's front legs is raised (as seen in the gallery of Roman and Renaissance works below).

Instead, the horse rears slightly, or may be striking off into a canter, with only its hind legs touching the ground, while Charles still holds the reins lightly, upright but at ease, implying his advanced horsemanship.

In the portrait, Titian achieves a feeling of steadiness and control through passages such as the darkly painted wood behind the rider, the evenly clouded sky, and Charles' detached, yet steely, gaze into the distance.

Goya's 1812 Equestrian Portrait of the 1st Duke of Wellington expands further, removing the sense of heroism, and presenting a diminished, isolated figure, undersized compared to his mount, almost overwhelmed by the landscape around him, and charging towards a dark skyscape.