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A section of the first electrical telegraph cable, used for a machine invented by William Fothergill Cook and Charles Wheatstone in London in 1837. Made of copper and wood, the cable was first used underground before it...

The world's first atomic clock, photograph by an unknown photographer, 1955. The photograph here shows the world's first caesium atomic clock, which was built in collaboration between Louis Essen (right) and Jack...

The Sumerians were the people of southern Mesopotamia (modern-day southern Iraq) whose civilization flourished between circa 4000 and 1750 BCE. Their name comes from the region, which is frequently – and incorrectly...

Map of the conflict between Caliph Ali (r. 656-661 CE) and Muawiyah I (r. 661 – 680 CE) during the First Fitna (656 – 661 CE), a civil war within the Rashidun Caliphate. The area shaded in green represents the territories...

Icon from the Mégalo Metéoron Monastery in Greece, representing the First Ecumenical Council of Nicaea in 325 CE, with the condemned Arius in the bottom of the icon.

Paul the Apostle undertook multiple missionary journeys across the Roman Empire to spread Christianity, establish churches, and strengthen the faith of early Christians. Paul's first missionary...

The First Anglo-Boer War (1880-1881) emerged from growing tensions following the British annexation of the South African Republic (Transvaal) in 1877 during...

An 1809 engraving by Thomas Rowlandson from an original drawing by Woodward showing the public's reaction to the first coal gas street lighting in Pall Mall, London in 1807. The new lights were invented by Frederick...

A model of the first telegraph machine developed by Samuel Morse (1791-1872) of Massachusetts, probably made around 1835. (Science Museum, London)

Water is Changed into Blood, the first of the ten plagues of Egypt, watercolor by James Tissot, before 1903.