100 BC

Millennium:	1st millennium BC
Centuries:	2nd century BC 1st century BC 1st century
Decades:	120s BC 110s BC 100s BC 90s BC 80s BC
Years:	103 BC 102 BC 101 BC 100 BC 99 BC 98 BC 97 BC

100 BC in various calendars

Gregorian calendar	100 BC C BC
Ab urbe condita	654
Ancient Egypt era	XXXIII dynasty, 224
- Pharaoh	Ptolemy X Alexander, 8
Ancient Greek era	170th Olympiad (victor)¹
Assyrian calendar	4651
Balinese saka calendar	N/A
Bengali calendar	−692
Berber calendar	851
Buddhist calendar	445
Burmese calendar	−737
Byzantine calendar	5409–5410
Chinese calendar	庚辰年 (Metal Dragon) 2598 or 2391     — to — 辛巳年 (Metal Snake) 2599 or 2392
Coptic calendar	−383 – −382
Discordian calendar	1067
Ethiopian calendar	−107 – −106
Hebrew calendar	3661–3662
Hindu calendars
- Vikram Samvat	−43 – −42
- Shaka Samvat	N/A
- Kali Yuga	3001–3002
Holocene calendar	9901
Iranian calendar	721 BP – 720 BP
Islamic calendar	743 BH – 742 BH
Javanese calendar	N/A
Julian calendar	N/A
Korean calendar	2234
Minguo calendar	2011 before ROC 民前2011年
Nanakshahi calendar	−1567
Seleucid era	212/213 AG
Thai solar calendar	443–444
Tibetan calendar	阳金龙年 (male Iron-Dragon) 27 or −354 or −1126     — to — 阴金蛇年 (female Iron-Snake) 28 or −353 or −1125

The world in 100 BC.

The eastern hemisphere in 100 BC.

Year 100 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Marius and Flaccus (or, less frequently, year 654 Ab urbe condita). The denomination 100 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

Roman Republic

• Consuls: Lucius Valerius Flaccus, Gaius Marius (Marius's sixth consulship).
• Manius Aquillius celebrates an ovation for victories in the Second Servile War.
• Lucius Appuleius Saturninus, a tribune, passes a law to redistribute land to military veterans. The law requires that all senators swear to abide by it. Quintus Caecilus Metellus Numidicus refuses and is exiled. He goes to Rhodes to study philosophy.
• December – Saturninus stands for consul for the following year. A rival candidate, Gaius Memmius, is found murdered by agents of Saturninus, who is declared a public enemy by the Senate. Marius, as consul, defeats his former ally in battle in the Forum. Saturninus and his followers surrender on condition that their lives are spared, but they are stoned to death with roof tiles by renegade senators.
• The building of the Sanctuary of Fortuna Primigenia, Palestrina, Italy, is begun. The model of it is now kept at the Museo Archeologico Nazionale, Italy (approximate date).

Asia Minor

• Tigranes II of Armenia is placed on Armenian throne by the Parthians in exchange for the cession of "seventy valleys". (approximate date)

Judea

• The deuterocanonical books of 1 and 2 Maccabees are written.

Asia

• Peasants revolt under Emperor Wu of Han. The Great Wall is extended out into the Gobi Desert, and sections of the wall are detached with signalling towers.
• Gandhara and Punjab are ruled by the Indo-Greek king Demetrius III Aniketos.
• A History of China is written by Sima Qian (approximate date).

America

• Mural room in the Maya pyramid at San Bartolo, Guatemala, painted.

• Olmec III period ends in Southeastern Mexico.

Births

• 
  Julius Caesar

• July 13 – Julius Caesar, Roman general and politician (d. 44 BC)
• Titus Labienus, Caesar's chief lieutenant in the conquest of Gaul (d. 45 BC)

Deaths

• Cornelia Africana, mother of Tiberius Gracchus (b. c. 190 BC)
• Lucius Appuleius Saturninus, Roman politician
• Theodosius of Bithynia, Greek astronomer and mathematician (b. c. 160 BC)