Millennium:	1st millennium BC
Centuries:	2nd century BC 1st century BC 1st century
Decades:	70s BC 60s BC 50s BC 40s BC 30s BC
Years:	58 BC 57 BC 56 BC 55 BC 54 BC 53 BC 52 BC

Politics
55 BC by topic
State leaders Political entities
Categories
Births Deaths
v t e

55 BC in various calendars
Gregorian calendar	55 BC LV BC
Ab urbe condita	699
Ancient Egypt era	XXXIII dynasty, 269
- Pharaoh	Ptolemy XII Auletes, 26
Ancient Greek era	181st Olympiad, year 2
Assyrian calendar	4696
Balinese saka calendar	N/A
Bengali calendar	−647
Berber calendar	896
Buddhist calendar	490
Burmese calendar	−692
Byzantine calendar	5454–5455
Chinese calendar	乙丑年 (Wood Ox) 2643 or 2436 — to — 丙寅年 (Fire Tiger) 2644 or 2437
Coptic calendar	−338 – −337
Discordian calendar	1112
Ethiopian calendar	−62 – −61
Hebrew calendar	3706–3707
Hindu calendars
- Vikram Samvat	2–3
- Shaka Samvat	N/A
- Kali Yuga	3046–3047
Holocene calendar	9946
Iranian calendar	676 BP – 675 BP
Islamic calendar	697 BH – 696 BH
Javanese calendar	N/A
Julian calendar	N/A
Korean calendar	2279
Minguo calendar	1966 before ROC 民前1966年
Nanakshahi calendar	−1522
Seleucid era	257/258 AG
Thai solar calendar	488–489
Tibetan calendar	阴木牛年 (female Wood-Ox) 72 or −309 or −1081 — to — 阳火虎年 (male Fire-Tiger) 73 or −308 or −1080

Year 55 BC was a year of the pre-Julian Roman calendar. At the time, it was known as the Year of the Consulship of Crassus and Pompey (or, less frequently, year 699 Ab urbe condita). The denomination 55 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: Marcus Licinius Crassus and Gnaeus Pompeius Magnus.
Consuls Marcus Licinius Crassus and Gnaeus Pompeius Magnus pass the Lex Trebonia.
Pompey's Theater, the first permanent (non-wooden) theatre in Rome is built. Built of stone on the Field of Mars, it included a temple to Venus Victorious, a public courtyard, and a meeting hall or curia in the far end near the "Sacred Area".
Fourth year of Julius Caesar's Gallic Wars:
- Spring – Julius Caesar starts the season campaigning in Illyricum (in the Balkan region) against the Pirustae, who have been raiding Roman territory.^[1]
- Summer – Julius Caesar defeats the Usipetes and the Tencteri, two Germanic tribes who have been driven across the Rhine River by the Suebi. He spreads Roman law and order, and makes the whole country as far as the Channel accessible to trade.
- May – Julius Caesar defeats a Germanic army then massacres the women and children, totalling 430,000 people, near the Meuse and Rhine Rivers (now known as the city of Kessel in the Netherlands).
- June – Julius Caesar crosses the Rhine River near modern-day Koblenz. He constructs a wooden bridge between Andernach and Neuwied (Germany).

Britain

August 22 or August 26 – Julius Caesar commands his first invasions of Britain, likely a reconnaissance-in-force expedition, in response to the Britons giving military aid to his Gallic enemies. Caesar retreats back to Gaul when the majority of his force is prevented from landing by storms.

Parthia

Mithridates IV, claimant to the throne of Parthia, supported by Aulus Gabinius, Roman governor of Syria, is defeated by Surena, general under Orodes, in the Battle of Seleucia.

Births

Tibullus, Roman Latin poet (approximate date)

Deaths

Archelaus, high priest of Comana (Cappadocia)
Berenice IV Epiphaneia, queen of Egypt (b. 77 BC)
Lucretius, Roman philosopher (b. c. 99 BC)
Quintus Caecilius Metellus Nepos, Roman consul
Quintus Caecilius Metellus Nepos Iunior, Roman consul
Tigranes the Great, Armenian Emperor (b. c. 140 BC)