The extraordinary quality and faithfulness of this copy of Titian's Charles V at the Battle of Mühlberg, which is slightly smaller than the original, has led on various occasions to its attribution to Alonso Sánchez Coello, an attribution supported by Maria Kusche (2003) with comparative arguments and documentary evidence. She compares this painting with other copies of works by the Venetian master that are documented as having been painted by Sánchez Coello, such as the Noli me tangere del Escorial or the Portrait of Emperor Ferdinand He notes that they share similar modifications in the hardening of the faces, in that they alternate randomly between precision of detail and greater simplification, and in that they tend to emphasise the figures and reduce the importance of the landscape. Moreover, an account found among the papers of Don John of Austria shows that he took advantage of his stay in Spain in 1575 to commission a large number of copies of portraits of the royal family - his own - from the king's painter, including, at the top of the list, "...".a portrait of the emperor on horseback, armed". Although this was not the only time Sanchez Coello painted the equestrian portrait of the emperor, as replicas are documented as gifts for the emperor of China and the Grand Duke of Tuscany, it is considered probable, as H.E. Wethey had previously pointed out, that this copy is the one he painted for the king's half-brother and which finally remained in the collection of the secretary Antonio Pérez, as reflected in the inventory of his possessions made in 1585.
However, none of the above arguments is conclusive. For Ángel Aterido (2000), this copy would not fit in with the production of either Sánchez Coello or Pantoja de la Cruz and, on account of the fluidity of the brushstroke and colouring, he would place the copy among the Madrid paintings of the mid-17th century, although he does not decide on any of the painters of that period who may have had free access to the royal collection and limits himself to vaguely suggesting the names of Juan Bautista Martínez del Mazo and Juan Carreño de Miranda.