AD 21 ( XXI) was a

common year starting on Wednesday A common year starting on Wednesday is any non-leap year (a year with 365 days) that begins on Wednesday, January 1, and ends on Wednesday, December 31. Its dominical letter hence is E. The current year, 2025, is a common year starting on Wedne ...

of the Julian calendar. At the time, it was known as the Year of the Consulship of

Tiberius Tiberius Julius Caesar Augustus ( ; 16 November 42 BC – 16 March AD 37) was Roman emperor from AD 14 until 37. He succeeded his stepfather Augustus, the first Roman emperor. Tiberius was born in Rome in 42 BC to Roman politician Tiberius Cl ...

and Drusus (or, less frequently, year 774 ''

Ab urbe condita ''Ab urbe condita'' (; 'from the founding of Rome, founding of the City'), or (; 'in the year since the city's founding'), abbreviated as AUC or AVC, expresses a date in years since 753 BC, 753 BC, the traditional founding of Rome. It is ...

''). The denomination AD 21 for this year has been used since the early medieval period, when the

Anno Domini The terms (AD) and before Christ (BC) are used when designating years in the Gregorian calendar, Gregorian and Julian calendar, Julian calendars. The term is Medieval Latin and means "in the year of the Lord" but is often presented using "o ...

calendar era A calendar era is the period of time elapsed since one '' epoch'' of a calendar and, if it exists, before the next one. For example, the current year is numbered in the Gregorian calendar, which numbers its years in the Western Christian era ...

became the prevalent method in Europe for naming years.

Events

By place

Roman Empire

* The Aedui revolt under Julius Florus and Julius Sacrovir; the revolt is suppressed by Gaius Silius. * Emperor Tiberius is a

Roman Consul The consuls were the highest elected public officials of the Roman Republic ( to 27 BC). Romans considered the consulship the second-highest level of the ''cursus honorum''an ascending sequence of public offices to which politicians aspire ...

for the fourth time. * The Romans create a

buffer state A buffer state is a country geographically lying between two rival or potentially hostile great powers. Its existence can sometimes be thought to prevent conflict between them. A buffer state is sometimes a mutually agreed upon area lying between t ...

in the territory of the

Quadi The Quadi were a Germanic peoples, Germanic people during the Roman era, who were prominent in Greek and Roman records from about 20 AD to about 400 AD. By about 20 AD they had a kingdom centred in the area of present-day western Slovakia, north ...

, in southern

Slovakia Slovakia, officially the Slovak Republic, is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the west, and the Czech Republic to the northwest. Slovakia's m ...

. * Barracks are constructed for the

Praetorian Guard The Praetorian Guard (Latin language, Latin: ''cohortes praetoriae'') was the imperial guard of the Imperial Roman army that served various roles for the Roman emperor including being a bodyguard unit, counterintelligence, crowd control and ga ...

, on the Quirinal (located on the Seven Hills of Rome).

Korea

* King Daeso of Dongbuyeo is killed in battle against the armies of

Goguryeo Goguryeo (37 BC – 668 AD) (; ; Old Korean: Guryeo) also later known as Goryeo (; ; Middle Korean: 고ᇢ롕〮, ''kwòwlyéy''), was a Korean kingdom which was located on the northern and central parts of the Korea, Korean Peninsula an ...

, led by its third ruler, King Daemusin.

By topic

Art and science

* The manufacture of

pen PEN may refer to: * (National Ecological Party), former name of the Brazilian political party Patriota (PATRI) * PEN International, a worldwide association of writers ** English PEN, the founding centre of PEN International ** PEN America, located ...

s and metal writing tools begins in

Rome Rome (Italian language, Italian and , ) is the capital city and most populated (municipality) of Italy. It is also the administrative centre of the Lazio Regions of Italy, region and of the Metropolitan City of Rome. A special named with 2, ...

(approximate date).

Births

Deaths

Arminius Arminius (; 18/17 BC–AD 21) was a chieftain of the Germanic peoples, Germanic Cherusci tribe who is best known for commanding an alliance of Germanic tribes at the Battle of the Teutoburg Forest in AD 9, in which three Roman legions under th ...

, Germanic military leader (b. 18/ 17 BC) * Clutorius Priscus, Roman poet (b. c. 20 BC) * Daeso of Dongbuyeo, Korean king (b. 60 BC) * Marcus Valerius Messalla Barbatus, Roman consul (b.

11 BC __NOTOC__ Year 11 BC was either a common year starting on Monday or Tuesday or a leap year starting on Sunday, Monday or Tuesday of the Julian calendar (the sources differ, see leap year error for further information) and a common year start ...

) *

Publius Sulpicius Quirinius Publius Sulpicius Quirinius (c. 51 BC – AD 21), also translated as Cyrenius, was a Roman aristocrat. After the banishment of the ethnarch Herod Archelaus from the tetrarchy of Judea in AD 6, Quirinius was appointed legate governor of Syria, ...

, Roman governor (b. c. 51 BC) *

Wang Wang may refer to: Names * Wang (surname) Wang () is the pinyin romanization of Chinese, romanization of the common Chinese surname (''Wáng''). It has a mixture of various origin with uncertain lineage of family history, however it is c ...

(or Xiaomu), Chinese empress of the

Xin Dynasty The Xin dynasty (; ), also known as Xin Mang () in Chinese historiography, was a short-lived Dynasties in Chinese history, Chinese imperial dynasty which lasted from 9 to 23 AD, established by the Han dynasty consort kin Wang Mang, who usurped th ...

References

{{DEFAULTSORT:21 0021 als:20er#21 1st millennium 1st century-related lists