The past leaves a trace.

Nuclear testing at the Nevada Test Site begins with Operation Ranger.

Nuclear testing at the Nevada Test Site begins with Operation Ranger.

Nuclear weapons tests are experiments carried out to determine the performance of nuclear weapons and the effects of their explosion. Over 2,000 nuclear weapons tests have been carried out since 1945. Nuclear testing is a sensitive political issue. Governments have often performed tests to signal strength. Because of their destruction and fallout, testing has seen opposition by civilians as well as governments, with international bans having been agreed on. Thousands of tests have been performed, with most in the second half of the 20th century.

First flight of the Lockheed P-38 Lightning.

First flight of the Lockheed P-38 Lightning.

The Lockheed P-38 Lightning is an American single-seat, twin-engined fighter aircraft that was used during World War II. Developed for the United States Army Air Corps (USAAC) by the Lockheed Corporation, the P-38 incorporated a distinctive twin boom design with a central nacelle containing the cockpit and armament. Along with its use as a general fighter, the P-38 was used in various aerial warfare roles, including as a fighter-bomber, a night fighter, and a long-range escort fighter when equipped with drop tanks. The P-38 was also used as a bomber-pathfinder, guiding streams of medium and heavy bombers, or even other P-38s equipped with bombs, to their targets.

Birth of Abbas I of Persia

Born: Abbas I of Persia (died 1629).

Pope Clement VI issues the papal bull Unigenitus, laying out the scriptural justification for indulgences,…

Pope Clement VI issues the papal bull Unigenitus, laying out the scriptural justification for indulgences, identifying only the Pope and episcopate as capable of accessing the treasury of merit, and establishing a jubilee year every half century.

Pope Clement VI, born Pierre Roger, was head of the Catholic Church from 7 May 1342 to his death, in December 1352. He was the fourth Avignon pope. Clement reigned during the first visitation of the Black Death (1348–1350), during which he granted remission of sins to all who died of the plague.

The co-emperors Stephen and Constantine are overthrown and forced to become monks by Constantine VII, who…

The co-emperors Stephen and Constantine are overthrown and forced to become monks by Constantine VII, who becomes sole emperor of the Byzantine Empire.

Stephen Lekapenos or Lecapenus was the second son of the Byzantine emperor Romanos I Lekapenos, and co-emperor from 924 to 945. With his younger brother Constantine, he deposed Romanos I in December 944, but they were overthrown and exiled a few weeks later by their brother in law, the legitimate emperor Constantine VII. Stephen lived out his life in exile on the island of Lesbos, where he died on Easter 963.

Death of Pope Vitalian

Died: Pope Vitalian.

Pope Vitalian was the bishop of Rome from 30 July 657 to his death in 672. His pontificate was marked by the dispute between the papacy and the imperial government in Constantinople over Monothelitism, which Rome condemned. Vitalian tried to resolve the dispute and had a conciliatory relationship with Emperor Constans II, who visited him in Rome and gave him gifts. Vitalian's pontificate also saw the secession of the Archbishopric of Ravenna from the papal authority.

Nika riots in Constantinople fail.

Nika riots in Constantinople fail.

The Nika riots, Nika revolt or Nika sedition took place against Byzantine emperor Justinian I in Constantinople over the course of a week in 532 AD. They are often regarded as the most violent riots in the city's history, with nearly half of Constantinople being burned or destroyed and tens of thousands of people killed.

Trajan succeeds his adoptive father Nerva as Roman emperor.

Trajan succeeds his adoptive father Nerva as Roman emperor.

Trajan was a Roman emperor from AD 98 to 117, remembered as the second of the Five Good Emperors of the Nerva–Antonine dynasty. He was a philanthropic ruler and a successful soldier-emperor who presided over one of the greatest military expansions in Roman history, during which, by the time of his death, the Roman Empire reached its maximum territorial extent. He was given the title of optimus princeps by the Roman Senate.