Rohrbach, Paul (b.1817; active 1850s-60s; German), after Hellwig, Theodor (1815-72; German)
H.R.H.Frederick William, Crown Prince of Prussia
Lithograph
Presented by the Prussian Government (by 1871?}
Unidentified; present location unknown

This print, identified as above in the NGV’s 1894 catalogue, cannot be identified with certainty.

It appears to have been presented at the same time as a lithograph of Frederick’s wife Victoria: see * Feckert after Winterhalter Victoria Adelaide, Princess Royal… {by 1871?} Loc? [PR]; and possibly also with * Milster William I, King of Prussia {by 1894} Loc? [PR] (showing Frederick William’s father). All 3 prints are listed in NGV 1894 as presented by the Prussian Government, presumably sometime between the marriage of Frederick and Princess Victoria in 1858, and the coronation of William I as German Emperor (1871).

Frederick (1831-88), also known as Fritz, reigned as Emperor for only 99 days before his death from cancer in 1888 (known as the year of the Three Emperors; he was succeeded by Wilhelm II). Although a military man, he was a liberal opposed to the aggressive policies of Bismarck, and, through his like-minded wife, close to Queen Victoria. 

Rohrbach is also known for other lithographed portraits: see photo.

[comparative photo: Rohrbach’s portrait of Schumann]

Refs.

NGV 1894, p.104 (V.Buvelot Gallery, 1st bay, no.74) 

For Frederick, see https://en.wikipedia.org/wiki/Frederick_III,_German_Emperor and http://www.unofficialroyalty.com/2015/02/ (detailed and informative entries) 

For Rohrbach (not listed in AKL), see Bénézit 11, p.1276 (with date of birth as above);   https://www.europeana.eu/portal/en/record/08547/84434E9EA93FAB5B0B3058DB68B9B2087013F1BC.html (lithographed portrait of Robert Schumann 1868), as reproduced here; and https://commons.wikimedia.org/wiki/File:Lithograph;_portrait_of_J._Muller,_Wellcome_L0006685.jpg (1858 print)

For Hellwig, see AKL 71 (2011), pp.376-77 and Bénézit 6, p.1358