521 BC

Millennium:	1st millennium BC
Centuries:	7th century BC 6th century BC 5th century BC
Decades:	540s BC 530s BC 520s BC 510s BC 500s BC
Years:	524 BC 523 BC 522 BC 521 BC 520 BC 519 BC 518 BC

521 BC in various calendars

Gregorian calendar	521 BC DXXI BC
Ab urbe condita	233
Ancient Egypt era	XXVII dynasty, 5
- Pharaoh	Darius I of Persia, 1
Ancient Greek era	64th Olympiad, year 4
Assyrian calendar	4230
Balinese saka calendar	N/A
Bengali calendar	−1113
Berber calendar	430
Buddhist calendar	24
Burmese calendar	−1158
Byzantine calendar	4988–4989
Chinese calendar	己卯年 (Earth Rabbit) 2177 or 1970     — to — 庚辰年 (Metal Dragon) 2178 or 1971
Coptic calendar	−804 – −803
Discordian calendar	646
Ethiopian calendar	−528 – −527
Hebrew calendar	3240–3241
Hindu calendars
- Vikram Samvat	−464 – −463
- Shaka Samvat	N/A
- Kali Yuga	2580–2581
Holocene calendar	9480
Iranian calendar	1142 BP – 1141 BP
Islamic calendar	1177 BH – 1176 BH
Javanese calendar	N/A
Julian calendar	N/A
Korean calendar	1813
Minguo calendar	2432 before ROC 民前2432年
Nanakshahi calendar	−1988
Thai solar calendar	22–23
Tibetan calendar	阴土兔年 (female Earth-Rabbit) −394 or −775 or −1547     — to — 阳金龙年 (male Iron-Dragon) −393 or −774 or −1546

The year 521 BC was a year of the pre-Julian Roman calendar. In the Roman Empire, it was known as year 233 Ab urbe condita. The denomination 521 BC 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

Persian Empire

• Darius I succeeded Gaumata as ruler of Persia.

Births

• Leonidas I. King of Sparta

Deaths

• March – Cambyses, ruler of ancient Persia (suicide)
• October – Gaumata, ruler of ancient Persia