Prosalentis was descended from a noble Byzantine family, who fled to areas under the control of the Venetian Republic after the Fall of Constantinople. His father was Pavlos Prosalentis, who is considered to be the first significant modern Greek sculptor and, in 1811, created Greece"s first art school.
Later, he finished his education at the Accademia di Belle Arti di Venezia.
His first name is sometimes seen as Spyros. His earliest lessons naturally came from his father. He remained in Italy until 1865 and, when he returned, received an appointment as Professor of painting at the Athens School of Fine Arts.
Foreign unknown reasons, he resigned from that position the following year and went back to Venice.
In 1876, a second chair of painting was established at the School of Fine Arts and he received another appointment as Professor, this time remaining in that position until his death. Upon commission from the Royal Family of Greece, he completed several series of portraits of notable personalities from the Greek Revolution, the University of Athens, and the War and Navy Departments.
He also painted some domestic genre scenes, but those are much less familiar.
