Ludovico (Luigi) Gonzaga (1539-95) was the third son of Federico Gonzaga and Margherita Paleologa. Sent at an early age to the French court, he spent most of his life there, achieving military distinction in the service of a number of French Kings. He became Captain of the Royal Guard in 1559 and a knight in the Order of St-Michael in 1561; this portrait appears to have been painted in between those two achievements. A squire prepares Ludovico for heavy cavalry duty on the field, evident from the inclusion of a lance rest, though the pauldrons (shoulder pieces) are yet to be applied. The portrait offers an important insight into the physical interaction between a soldier and his valet, drawing attention to the arming point used to attach the vambrace (arm defence) to the arming doublet. North Italian in style, the armour displays a skilful blackened finish with gilded rope edges. A pinkish tie on Ludovico's leg below denotes an unidentified political allegiance. In his left hand he holds a letter, his right rests on a table covered with a deep green cloth and a map, on which rests a helmet.

The sitter can be identified by the painting’s clear relationship to an inscribed bust-length portrait of Ludovico in the Schloss Ambras series, in which the expression, setting and lighting of the head are identical, and the same suit of armour is completed by the pauldrons not yet fitted in this scene. Shortly after this portrait, in 1565, Ludovico married Henriette of Cleves, thereby becoming Duke of Nevers.