Schlegel immediately commissioned Wolf to work on some plates for "Traité de Fauconnerie". The result was a set of "magnificent paintings of birds of prey in life size" which established Wolf's reputation in Europe. At the age of 20, Wolf was to appear at Maien to join the Army. As a fit young man with sharp-shooting abilities he could not be rejected, but it was peacetime and the surgeon, who knew him, helped him avoid recruitment under the pretext of a weak chest. Back in Darmstadt, Wolf went on working on bird plates, and joined an art school where he worked on portraits, landscapes and copying of works in the Darmstadt Gallery. He was a keen observer of wild birds and once had a pit dug in which he sat all day to watch the courtship of black grouse. In 1847, he left Darmstadt to join the Antwerp Academy to learn the Dutch oil painting techniques. Around this time, Kaup visited the British Museum, he was asked about the German artist who did the plates for Schlegel's book, and Wolf was invited to London to illustrate the genera of birds for a book by George Robert Gray. Wolf travelled to London on 20th March 1848 on the Soho, and was introduced by David William Mitchell, an amateur illustrator himself and a secretary of the Zoological Society of London, to Trübner of Longmans publishing. The very next day was set to work on Gray's "The Genera of Birds". While at work in the insect room of the British Museum, he met other naturalists including J O Westwood with whom he could converse in French. He was a friend of William Russell, an accountant and a Campbell related to the Duke of Argyll. Russell brought Sir Edwin Landseer and the Duke of Argyll to see the works of Wolf. The Duke soon became a patron and he was also introduced to the Duke of Westminster. Wolf's paintings were also appreciated by the Pre-Raphaelite Brotherhood of London. John Gould admired Wolf and would have liked him on his staff, but Wolf only contributed illustrations on a freelance basis. Wolf accompanied Gould on a collection trip to Norway. Wolf thought of Gould as a shrewd and uncouth man. Wolf also noted that Gould lacked a knowledge of feather patterning, apart from knowing nothing about composition, with a tendency to add too much colour, claiming that specimens in the wild were brighter. Wolf was commissioned by the Zoological Society of London to paint a watercolour of wapiti deer in the snow; it is dated January 1881.