The year of the four emperors: Did you mean...?

This map illustrates the four voyages of Christopher Columbus between 1492 and 1504, commissioned by Queen Isabella I of Castile (reign 1474–1504) and King Ferdinand...

This infographic illustrates the Varna caste system in ancient India. First mentioned in the Rig Veda's Purusha Sukta c. 1200–1000 BCE, it shows society divided into four groups that emerged from the...

A painting of four monks by Claudio Rinaldi (1852-1909 CE). (Dorotheum, Munich)

A photograph of the 'Big Four' leaders at the Paris Peace Conference at Versailles which decided peace terms after the First World War (1914-18). Left to Right: Prime Minister of Italy Vittorio Orlando (1860-1952...

Porphyry sculpture portraying the four Tetrarchs (Diocletian, Maximianus, Galerius and Constantius Chlorus) embracing. It is dated to c. 300 CE and was sculpted in Asia Minor. It probably originally decorated two separate...

Four Horsemen of the Apocalypse, oil on canvas painting by Viktor Vasnetsov, 1887. Glinka National Museum Consortium of Musical Culture, Moscow.

The Four Elements. Painting by Mana Lesman. Used with the permission of the artist.

The Egyptian 'Four Dogs' cosmetic palette. Louvre, Paris.

Marble portrait heads of four Greek philosophers (Socrates, Antisthenes of Athens, Chrysippus, and Epicurus), Roman copies after Hellenistic originals. The British Museum, London.

Eos in her four-horse chariot, detail of terracotta red-figure lekanis vase attributed to the Stuttgart group, from Canosa, late 300s BCE. Metropolitan Museum of Art, New York.