An inscription on the front of the shield reads, "GEORGIVS DE GHISYS MNTVANZ FA M.D.LIIII".
Ghisi was an artist, mainly a printmaker, from Mantua, but he was in the Netherlands from about 1550 to about 1555, and the shield was probably made in Antwerp, then under the rule of the Habsburgs.
It is embossed with repoussé and chased work in high relief, with a framed central circular scene of battling horseman, surrounded by four strapwork cartouches containing allegorical female figures (Victory, Fame, Fortitude, Prudence).
The frames around the five main scenes themselves incorporate detailed images on a much smaller scale, taken from the Iliad and ancient mythology, inlaid in gold.
For example, an iron shield held by the Kunsthistorisches Museum in Vienna has similar strapwork and embossed imagery with scenes of Jason and the Golden Fleece; and a similar gilded shield or rondache at the Hermitage in St Petersburg has four allegorical figures (Prudence, Fortitude, Fame, Envy) arranged in circular cartouches around a circular image of Mars.