Men, boys, and artists. And dogs.

James Achilles Kirkpatrick (at 16), by Nathaniel Hone the Elder, 1780.

Marc Chagall, by Yuri (Yehuda) Pen, 1914.

Unknown, circa mid-nineteenth century.

Grand Duke Konstantin Konstantinovich, by Osip Braz, 1912.

The Boy with the Arrow, by Douglas Volk, 1903.

Agasse with a bulldog, by Firmin Massot and Jacques-Laurent Agasse, circa 1795.

Prince Kazimierz Nestor Sapieha, by Józef Pitschmann, 1787.

Robert S. Day as Rex, King of Carnival, unknown photographer, 1892.

Detail of below.

Segismundo Moret y Quintana, by Federico de Madrazo y Kuntz, 1855.

Jaime Girona, later first conde de Eleta, by Federico de Madrazo y Kuntz, 1856.

Unknown, circa second half of the nineteenth century. (Courtesy Ralf de Jonge.)

Portrait of a Young Nobleman, by Jacob Ferdinand Voet (?), circa 1670s-80s.

Joven sentado con libro, Gerardo Sacristán Torralba, 1930.

Self-portrait, by Louis Meijer, 1838.

Rudolph Valentino with his Irish wolfhound Centaur Pendragon, Chicago, circa 1925.

Detail of below.

Patrick Heatly, by Johan Zoffany, circa 1783-87.

Giacomo Meyerbeer (composer, born Jacob Liebmann Beer), by Friedrich Georg Weitsch, 1802.

Eustaquio Marín Ramos (painter), by José Villegas Cordero, 1900.

Unknown, circa first half of twentieth century.

Herthier de Boislambert, by Wojciech Kossak, 1924.

Head of a Young Man, also known as Portrait of a Sailor, by John Singer Sargent, 1878.

Self-portrait, by Nikolai Alexandrovich Yaroshenko, 1894.

"Souvenir de Charles de Pape à ses chers cousins de Bruxelles, 22 08 1904." (Courtesy Ralf de Jonge.)

William Burlton Bennet en chasseur (in hunting costume), by Henri-Pierre Danloux, 1802.

Autoportret z paletą, by Teodor Axentowicz, 1898.

John Barrymore, 1897.

Peotr Lachinov, by Henri-François Riesener, circa 1820-22.

Unknown, circa early twentieth century. (?)

Thomas Hooke Pearson, by George Chinnery, circa 1824.

Unknown man, formerly known as James Scott Duke of Monmouth and Buccleuch, unknown artist, circa 1640s.

Self-portrait in Pink, by Domenico Baccarini, 1903.

William Henry Betty as Young Norval in "Douglas" by James Heath, by John Opie, 1804.