Arab horsemen.

Adolf Schreyer (July 9, 1828 Frankfurt-am-Main – July 29, 1899 Kronberg im Taunus) was a German painter, associated with the Düsseldorf school of painting. His subjects and style of this painting are closely related to the Arabian scenes of Delacroix and Fromentin. His preferred subject matter was the Arab rider and his horse. While in Algeria, Schreyer immersed himself in the local culture, learning several Arab dialects and riding with Bedouin horsemen.

He studied art first at the Städel Institute in his native town, and then at Stuttgart and Munich. He painted many of his favorite subjects in his travels in the East. He first accompanied Maximilian Karl, 6th Prince of Thurn and Taxis through Hungary, Wallachia, Russia and Turkey, then, in 1854, he followed the Austrian army across the Wallachian frontier. In 1856 he went to Egypt and Syria, and in 1861 to Algiers. In 1862 he settled in Paris, but returned to Germany in 1870 and settled at Cronberg near Frankfurt, where he died.

Schreyer was, and is still, especially esteemed as a painter of horses, of peasant life in Wallachia and Moldavia, and of battle incidents. His work is remarkable for its excellent equine draughtsman ship, and for the artist's power of observation and forceful statement.
The Metropolitan Museum, New York owns three of Schreyer's oriental paintings: Abandoned, Arabs on the March and Arabs making a detour, and many of his best pictures are in the Rockefeller family, Vanderbilt family, John Jacob Astor, William Backhouse Astor, Sr., August Belmont, and William Walters collections. (Wikipedia). He also painted several pictures of the outposts along the roads of Wallachia, a part of present-day Romania. His paintings are difficult to date because the chronology of his work has not been established.

Reference: Paine Art Center and Arboretum, Oshkosh (Wise), 1972, p. 57.