On the night of 23–24 April 1915, known as Red Sunday, the Ottoman government rounded up and imprisoned an estimated 250 Armenian intellectuals and community leaders of the Ottoman capital, Constantinople, and later those in other centers, who were moved to two holding centers near Angora (Ankara).
President Gerald Ford had given a televised speech on 23 April, declaring an end to the Vietnam War and all U.S. aid. Frequent Wind continued around the clock, as North Vietnamese tanks breached defenses on the outskirts of Saigon.
In preparation for Operation Beit ol-Moqaddas, the Iranians had launched numerous air raids against Iraq air bases, destroying 47 jets (including Iraq's brand new Mirage F-1 fighter jets from France); this gave the Iranians air superiority over the battlefield while allowing them to monitor Iraqi troop movements.
On 23 April, in a meeting of around 40 students from 21 universities, the Beijing Students' Autonomous Federation (also known as the Union) was formed. It elected CUPL student Zhou Yongjun as chair. Wang Dan and Wu'erkaixi also emerged as leaders. The Union then called for a general class boycott at all Beijing universities. Such an independent organization operating outside of party jurisdiction alarmed the leadership.
On 23 April 2000, a 22-vehicle convoy carrying ammunition and other supplies to an airborne unit was ambushed near Serzhen-Yurt in the Vedeno Gorge by an estimated 80 to 100 "bandits", according to General Troshev.
On April 23, Beijing announced that all primary and secondary schools would be closed for two weeks. A few days before, some colleges in Peking University had been closed because some students had been infected.
On April 23, China announced that a 53-year-old woman had died on April 19, its first SARS death since June. Two other cases were found, who were both healthcare workers, one of which was the deceased woman's daughter. The outbreak originated from a researcher working on the SARS virus in a lab at the Institute of Virology in Beijing, who inadvertently caught the disease and ended up spreading it to the nurse taking care of him.
On 23 April 2014, OnePlus began its "Smash the Past" campaign. The promotion asked selected participants to destroy their phones on video in an effort to purchase the OnePlus One for $1 (US). Due to confusion, several videos were published by unselected users misinterpreting the promotion and destroying their phones before the promotion start date. OnePlus later revised the rules of their promotion by allowing consumers to donate their old phones. There were 140,000 entrants in the contest with 100 winners.
On April 23, 2014, the Federal Communications Commission (FCC) was reported to be considering a new rule that would permit Internet service providers to offer content providers a faster track to send content, thus reversing their earlier net neutrality position.
On April 23, 2014, Slim took control of Telekom Austria, Austria's biggest phone carrier, which has telcos in countries such as Bulgaria, Croatia and Belarus, under a 10-year agreement, was Slim's first successful business acquisition in Europe.
Goulding appeared on the Major Lazer album Peace Is the Mission on the track "Powerful", alongside Tarrus Riley. The track was released together with the album on 1 June 2015. A preview of the single was revealed on 23 April 2015.
On 23 April 2016, Charles appeared in a comedy sketch for the Royal Shakespeare Company's Shakespeare Live! at the Royal Shakespeare Theatre, to commemorate the 400th anniversary of William Shakespeare's death in 1616. The event was televised live by the BBC. Charles made a surprise entrance to settle the disputed delivery of Hamlet's celebrated line, "To be or not to be, that is the question".