21

AD 21 in other 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); 2717 or 2657; — to —; 辛巳年 (Metal Snake); 2718 or 2658
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

Millennium:	1st millennium
Centuries:	1st century BC – 1st century – 2nd century
Decades:	0s BC 0s 10s – 20s – 30s 40s 50s
Years:	18 19 20 – 21 – 22 23 24

21 is a year in the 1st century. It was a common year starting on Wednesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Augustus and Caesar.

Events

Revolt of the Aedui under Julius Florus and Julius Sacrovir, suppressed by Gaius Silius.
Tiberius is a Roman Consul for the fourth time.
Beginning of the revolt in Africa led by Tacfarinas.
The Romans create a buffer state in the territory of the Quadi in southern Slovakia.
Construction of a barracks for the Praetorian Guard on the Quirinal.
Pens and metal writing tools are made in Rome.