On this Day

ON THIS DAY: Halley first observed his eponymous comet (1682)

On 26 August 1682, English astronomer Edmond Halley personally observed a comet streaking across the night sky. It was not his first professional study,...

ON THIS DAY: Council of Nicaea defined Christian Orthodoxy (325)

On this day in 325 AD, the Council of Nicaea concluded after weeks of fierce debate that would shape the future of Christianity. Convened...

ON THIS DAY: The Red Cross is founded (1864)

Origins in the 19th century The roots of the Red Cross trace back to the mid-19th century, when Swiss businessman Henry Dunant witnessed the carnage...

On This Day: Leon Trotsky assassination in Mexico (1940)

On this day in 1940, the world learned of the assassination of Leon Trotsky, a defining moment in the brutal rivalries of the Soviet...

ON THIS DAY: The link between mosquitoes and malaria is discovered (1897)

Sir Ronald Ross discovers the link between mosquitoes and malaria On 20 August 1897, Dr Ronald Ross, a British doctor working in India, made a...