The 1st century was the century spanning AD 1 (represented by the Roman numeral I) through AD 100 (C) according to the Julian calendar. It is often written as the 1st century AD or 1st century CE to distinguish it from the 1st century BC (or BCE) which preceded it. The 1st century is considered part of the Classical era, epoch, or historical period. The Roman Empire, Han China and the Parthian Persia were the most powerful and hegemonic states.

During this century, the Roman Empire (ruled by the Julio-Claudian and Flavian dynasties) continued to be in a period of relative stability known as Pax Romana, withstanding a financial crisis in 33 and a civil war in 69. In Europe, Rome expanded into Britain and fought wars in Germania and Dacia. In Africa, Rome was challenged by Tacfarinas, who led his own Musulamii tribe and a loose and changing coalition of other Berber tribes before being defeated in 24. In West Asia, Rome defeated a Jewish rebellion (66–73) and fought a war with Parthia from 58–63, though the latter conflict was inconclusive. In East Asia, the Chinese Western Han dynasty was overthrown and replaced by the Xin dynasty in 9, which in turn faced its own rebel movements (namely the Red Eyebrows and Lulin), and was replaced by the Eastern Han dynasty in 25. The Eastern Han dynasty then faced and quelled a rebellion by the Trưng sisters (40–43). In 58, the Eastern Han dynasty entered a golden age with the Rule of Ming and Zhang, who were generally regarded as able administrators who cared about the welfare of the people and who promoted officials with integrity. On its northern frontier, the Chinese dynasties waged intermittent war with the Xiongnu before emerging victorious in 91. The states of Funan and Xianbei were also established in this century.

The century saw the origination of Christianity from Palestine. In the early 30s, Roman governor Pontius Pilate sentenced Jesus to crucifixion; his suffering and redemptive death by crucifixion would become central aspects of Christian theology concerning the doctrines of salvation and atonement. Anti-Jewish riots broke out in Alexandria in 38. In 64, the Great Fire of Rome destroyed two-thirds of the city, precipitating the empire's first persecution of Christians, who were blamed for the disaster. Later in 70, the siege and subsequent sack of Jerusalem and the Second Temple during the First Jewish–Roman War marked a major turning point in Jewish history. The loss of mother-city and temple necessitated a reshaping of Jewish culture to ensure its survival. Judaism's Temple-based sects, including the priesthood and the Sadducees, diminished in importance. Second Temple Judaism came to an end, while a new form of Judaism that became known as Rabbinic Judaism developed out of the Pharisaic school. Furthermore, the White Horse Temple, the first Buddhist temple in China, was traditionally constructed in 68, though it is not recorded in contemporary sources before 289.

Several natural disasters took place in this century. In 17, an earthquake struck the region of Lydia in the Roman province of Asia in Asia Minor (now part of Turkey), causing the destruction of at least 12 cities, with Sardis being most affected. Around 44 to 48, a famine took place in Judea, precipitating assistance by Helena of Adiabene and her son, Izates II. In 62, an earthquake of an estimated magnitude of between 5 and 6 and a maximum intensity of IX or X on the Mercalli scale struck the towns of Pompeii and Herculaneum, severely damaging them. The towns of Pompeii and Herculaneum both suffered major damage, with damage to some buildings also reported from Naples and Nuceria. In 79, Mount Vesuvius violently spewed forth a deadly cloud of super-heated tephra and gases to a height of 33 km (21 mi), ejecting molten rock, pulverized pumice and hot ash. The event destroyed several towns and minor settlements in the area, at the time part of the Roman Empire, with Pompeii and Herculaneum being the most famous examples. The total population of both cities was over twenty thousand. The remains of over 1,500 people have been found at Pompeii and Herculaneum so far, although the total death toll from the eruption remains unknown.^{[citation needed]} Death toll estimates range from 13,000 to 16,000.

The 0s began on January 1, AD 1 and ended on December 31, AD 9, covering the first nine years of the Common Era.

In Europe, the 0s saw the continuation of conflict between the Roman Empire and Germanic tribes in the Early Imperial campaigns in Germania. Vinicius, Tiberius and Varus led Roman forces in multiple punitive campaigns, before sustaining a major defeat at the hands of Arminius in the Battle of the Teutoburg Forest. Concurrently, the Roman Empire fought the Bellum Batonianum against a rebelling alliance of native peoples led by Bato the Daesitiate in Illyricum, which was suppressed in AD 9. A conflict also took place in Korea, where Daeso, King of Dongbuyeo invaded Goguryeo with a 50,000-man army in AD 6. He was forced to retreat when heavy snow began to fall, stopping the conflict until the next decade. In China, the last ruler of the Chinese Western Han dynasty (Ruzi Ying) was deposed, allowing Wang Mang to establish the Xin dynasty.

Literary works from the 0s include works from the ancient Roman poet Ovid; the Ars Amatoria, an instructional elegy series in three books, Metamorphoses, a poem which chronicles the history of the world from its creation to the deification of Julius Caesar within a loose mythico-historical framework, and Ibis, a curse poem written during his years in exile across the Black Sea for an offense against Augustus. Nicolaus of Damascus wrote the 15-volume History of the World.

Estimates for the world population by AD 1 range from 170 to 300 million. A census was concluded in China in AD 2: final numbers showed a population of nearly 60 million (59,594,978 people in slightly more than 12 million households). The census is one of the most accurate surveys in Chinese history. (Full article...)