AD 21

Millennium:	1st millennium
Centuries:	1st century BC 1st century 2nd century
Decades:	0s 10s 20s 30s 40s
Years:	18 19 20 AD 21 22 23 24

AD 21 in various calendars

Gregorian calendar	AD 21 XXI
Ab urbe condita	774
Assyrian calendar	4771
Balinese saka calendar	N/A
Bengali calendar	−572
Berber calendar	971
Buddhist calendar	565
Burmese calendar	−617
Byzantine calendar	5529–5530
Chinese calendar	庚辰年 (Metal Dragon) 2718 or 2511     — to — 辛巳年 (Metal Snake) 2719 or 2512
Coptic calendar	−263 – −262
Discordian calendar	1187
Ethiopian calendar	13–14
Hebrew calendar	3781–3782
Hindu calendars
- Vikram Samvat	77–78
- Shaka Samvat	N/A
- Kali Yuga	3121–3122
Holocene calendar	10021
Iranian calendar	601 BP – 600 BP
Islamic calendar	619 BH – 618 BH
Javanese calendar	N/A
Julian calendar	AD 21 XXI
Korean calendar	2354
Minguo calendar	1891 before ROC 民前1891年
Nanakshahi calendar	−1447
Seleucid era	332/333 AG
Thai solar calendar	563–564
Tibetan calendar	阳金龙年 (male Iron-Dragon) 147 or −234 or −1006     — to — 阴金蛇年 (female Iron-Snake) 148 or −233 or −1005

AD 21 (XXI) was a common year starting on Wednesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Tiberius and Drusus (or, less frequently, year 774 Ab urbe condita). The denomination AD 21 for this year has been used since the early medieval period, when the Anno Domini calendar 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 for the fourth time.

• The Romans create a buffer state in the territory of the Quadi, in southern Slovakia.
• Barracks are constructed for the Praetorian Guard, on the Quirinal (located on the Seven Hills of Rome).

Korea

• King Daeso of Dongbuyeo is killed in battle against the armies of Goguryeo, led by its third ruler, King Daemusin.

By topic

Art and Science

• The manufacture of pens and metal writing tools begins in Rome (approximate date).

Deaths

• Arminius, 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)
• Publius Sulpicius Quirinius, Roman governor (b. c. 51 BC)
• Wang (or Xiaomu), Chinese empress of the Xin Dynasty