10. April

On 10 April 837 the comet passed about 5 million kilometres from Earth, the closest of any return on record. Tang court astronomers in Chang’an followed its tail as it swept across the sky. In Francia, the Emperor Louis the Pious, fearing it foretold the death of a prince, gave himself to prayer…

The People’s Charter asked for six things, starting with a vote for every man and a secret ballot. Parliament rejected petitions in 1839, 1842 and 1848, the second signed by more than three million people. The movement faded after a mass meeting on Kennington Common in April 1848.

The former bass player had left the band to study art in Hamburg and stay with Astrid Kirchherr. He died of a brain haemorrhage at 21. Lennon, McCartney and Best flew in the next day for the Star-Club and heard the news from Kirchherr at the airport.

Do you foresee a time when Lennon–McCartney becomes an active songwriting partnership again? — No. A question-and-answer sheet sent out with copies of his solo album said he had no plans to record with the Beatles. The Daily Mirror’s front page read “Paul Quits The Beatles”. Their last album, Let…

A Polish immigrant, Janusz Waluś, shot the popular leader of the Communist Party outside his home, with a gun supplied by a Conservative Party politician. An Afrikaner neighbour took down the car’s number. As the country teetered, it was Mandela, not de Klerk, who went on national television to…

A Polish immigrant, Janusz Waluś, shot the leader of the Communist Party in his driveway at Dawn Park. A neighbour, an Afrikaner woman, took the number of his car. Mandela went on television to appeal for calm: “A white woman, of Afrikaner origin, risked her life so that we may know, and bring to…

Five hours before 44 senators. Asked by Orrin Hatch how Facebook made money when users paid nothing, Zuckerberg answered: “Senator, we run ads.”

In April 2017 eight observatories from Hawaii and Chile to Spain and the South Pole, timed by atomic clocks, observed together as a telescope the size of the Earth. Their data went by aeroplane on hard drives. Two years later six press conferences showed the shadow of the black hole in M87.