c. 509 BC – (legendary)Overthrow of the Roman monarchy[2] – According to the traditional account, Roman aristocrats expel Etruscan king Lucius Tarquinius Superbus, abolish the Roman Kingdom and establish the Roman Republic. Many details are generally accepted to be fictional, but scholars disagree about the degree to which the legendary narratives may or may not have a foundation in historical fact.
c. 508 BC – War between Clusium and Aricia – According to Livy, King Lars Porsena of the Etruscan city of Clusium besieged Rome on behalf of Tarquinius Superbus. The outcome is debated, but tradition states that it was a Roman victory. The Clusians then besieged the Latin town of Aricia, which received support from the Latin League as well as the Greek colony of Cumae and destroyed the Clusian army. Livy doesn't say whether the Romans participated as allies of Aricia, but defeated and surviving Etruscan soldiers were given refuge and medical treatment in Rome. He claimed some who stayed behind were given homes in a neighbourhood later known as the 'Tuscan quarter'.[3]
Battle of Colline Gate (477 BC) – Consul Gaius Horatius Pulvillus has indecisive victory over the Etruscan civilization soon after the Battle of the Temple of Hope.
295 BC – Battle of Sentinum – Romans under Fabius Rullianus and Publius Decimus Mus defeat the Samnites and their Etruscan and Gallic allies, forcing the Etruscans, Gauls, and Umbrians to make peace
Battle of Cape Ecnomus – A Carthaginian fleet under Hamilcar and Hanno is defeated in an attempt to stop a Roman invasion of Africa by Marcus Atilius Regulus.
Battle of Adys – Romans under Regulus defeat the Carthaginians in North Africa
255 BC – Battle of Tunis – Carthaginians under Xanthippus, a Greek mercenary, defeat the Romans under Regulus, who is captured.
251 BC – Battle of Panormus – Carthaginian forces under Hasdrubal are defeated by the Romans under L. Caecilius Metellus.
Battle of Ager Falernus – Avoiding destruction with deceit, Hannibal escapes Fabius' trap in this small skirmish.
216 BC –
Battle of Cannae – Hannibal destroys the main Roman army of Lucius Aemilius Paulus and Publius Terentius Varro in what is considered one of the great masterpieces of the tactical art.
146 BC – Battle of Corinth – Romans under Lucius Mummius defeat the Achaean League forces of Kritolaus, who is killed. Corinth is destroyed and Greece comes under direct Roman rule.
Roman–Parthian war of 54–53 BCE. This conflict resulted from the Parthian war of succession (57–54 BCE) between Mithridates IV and his brother Orodes II after killing their father, king Phraates III. The Roman invasion of Parthia, commencing in 54 BCE and ending catastrophically at the Battle of Carrhae in 53 BCE, was partially motivated by or justified as supporting Mithridates' claim to the Parthian throne.[6]
25–22 BC - Gaius Petronius' expeditions against Nubia - Roman forces managed to reach Qasr Ibrim and northern Nubia, capturing several cities, including Pselcis, Primis, Abuncis, Phthuris, Cambusis, Attenia, and Stadissias, then destroyed the city of Napata (kushite capital) and other cities in retaliation while taking captives. Kushites Kandake earns a favorable peace treaty and Romans established a new frontier at Hiere Sycaminos (Maharraqa), halting Rome's southward expansion in Africa.
25 BC Siege of Eudaemon - The supporting Roman fleet, after crossing the Gulf of Aqaba, occupied and sacked the port of Aden, securing the Roman merchant route to India in Red Sea. However, Roman interests wouldn't be served by a second expedition, becoming clear that certain fringes of the empire (like Nubia or Arabia) could not be won except at greater costs, being careful of further military adventures.
Roman expeditions to Lake Chad and the Niger River (19 BC–90 AD): Roman expeditions (two in the western Sahara, two in the central Sahara, and one in the area of Lake Chad) to subdue warring tribes in the area (like the warlike nomadic tribe of the Garamantes who lived in the current region of Fezzan) or to achieve the elimination of taxes on the nomads of the Sahara and plan possible routes of conquest to Sub-Saharan Africa, or at least control the Trans-Saharan caravan routes and penetrate into the kingdoms of the pygmies.
83/84 – Battle of Mons Graupius. Romans under Gnaeus Julius Agricola defeat the Caledonians and temporally expanded Roman rule north into Caledonia (modern Scotland), establishing the northernmost Roman forts, like Cawdor, Tarradale and Portmahomack. Also, the fleet sailed north and made the first known circumnavigation of Britain, whereupon it was definitely discovered to be an island. It was proclaimed that Agricola had finally subdued all the tribes of Britain,[9] however, the costs of a drawn-out war outweighed any economic or political benefit and it was deemed more profitable to leave the Caledonians to themselves and dismantled Roman fortifications after Southern Uplands.[10]
363, 29 May – Battle of Ctesiphon – Emperor Julian defeats Shapur II of Persia outside the walls of the Persian capital, but is unable to take the city.
363, June – Battle of Samarra (363) – Julian fights the Sassanids and is subsequently killed in battle. Though indecisive, the battle leads to massive losses for the Roman Empire through a forced peace treaty.
406, 31 December – traditional date of the Crossing of the Rhine: a mixed group of barbarians, which purportedly included Vandals, Alans and Suebi, crossed into northern Gaul.[13]
Another Visigothic invasion of Italy led by Alaric I (c. 408–410)[16][17]
409: Battle of Ostia – Visigoths under Alaric I defeated the Romans.
413 – Siege of Massilia – Visigoths under Ataulf were defeated by Romans under Bonifacius while trying to besiege the Roman city. They made peace with Rome soon after.
Roman–Sasanian War of 421–422 - The Eastern Roman Emperor Theodosius II declared war against the Persians and obtained some victories, but in the end, the two powers agreed to sign a peace on the status quo ante.
422 – Battle of Tarraco – The Vandal king Gunderic defeat the Western Romans, making the Vandals the undisputed masters of Hispania.
Battle of Arelate – The Western Roman Emperor Majorian, with the support of Aegidius and Nepotianus, defeated the Visigoths at Arlate. With a treaty, the Visigothic returned all territory in Hispania to the Romans.
461 – Battle of Cartagena – A Vandal fleet surprised and destroyed the Roman fleet.
472 – Siege of Rome - Ricimer, having fallen out with his choice for Roman Emperor, allied with the Burgundians and Germans under Odoacer, defeated and killed the Western Roman Emperor Anthemius.
^Webster, Jane (1996). "Ethnographic barbarity: colonial discourse and 'Celtic warrior societies'.". In Cooper, Nick (ed.). Roman Imperialism: Post-Colonial Perspectives(PDF). School of Archaeological Studies, University of Leicester. pp. 117–118. Retrieved 5 April 2023.
^Tacitus claims that Orkney was "discovered and subdued", but Thomson (2008) pp. 4–5 is as sceptical about Tacitus's claims on behalf of Agricola as he is about Claudius's earlier subjugation of Orkney (see above).
Boin, Douglas (2020). Alaric the Goth: An Outsider's History of the Fall of Rome. New York: W.W. Norton & Co. ISBN978-0-39363-569-0.
Jones, Jim (2013). "Roman History Timeline"(PDF). West Chester University of Pennsylvania. Archived from the original(PDF) on 2 April 2023. Retrieved 2 April 2023.