- EmperorTitus completes and inaugurates the Colosseum with 100 days of games.
- The earliest stage of LullingstoneRoman villa is built.
- The Roman occupation of Britain reaches the River Tyne–Solway Firth frontier area. Gnaeus Julius Agricola creates a fleet for the conquest of Caledonia; he finally proves that Britannia is an island.
- Legio II Adiutrix is stationed at Lindum Colonia (modern Lincoln). The city is an important settlement for retired Roman legionaries.
- The original Roman Pantheon is destroyed in a fire, together with a large number of additional buildings.
- The Eifel Aqueduct is constructed to bring water 95 km (59 mi) from the Eifel region to Colonia Claudia Ara Agrippinensum (modern Cologne).
- Gnaeus Julius Agricola begins his invasion of Scotland.
- Some 30,000 Asian tribesmen migrate from the steppes to the west with 40,000 horses and 100,000 cattle, joining with Iranian tribesmen and with Mongols from the Siberian forests to form a group that will be known in Europe as the Huns.
Arts and sciences
- Domitian succeeds his brother Titus as emperor. Domitian isn't a soldier like his two predecessors, and his administration is directed towards the reinforcement of a monarchy. By taking the title of Dominus ("lord"), he scandalises the senatorial aristocracy. Romanisation progresses in the provinces, and life in the cities is greatly improved. Many provincials – Spanish, Gallic, and African – become Senators.
- The Arch of Titus is constructed.
- Pliny the Younger is flamen Divi Augusti (priest in the cult of the Emperor).
- The silver content of the Roman denarius rises to 92 percent under emperor Domitian, up from 81 percent in the reign of Vitellius.
- Roman emperorDomitian becomes Roman Consul.
- Gnaeus Julius Agricola raises a fleet and encircles the Celtic tribes beyond the Forth, the Caledonians rise in great numbers against the Romans. They attack the camp of Legio IX Hispana at night, but Agricola sends his cavalry in and put them to flight.
- Calgacus unites the Picts (30,000 men) in Scotland and is made chieftain of the Caledonian Confederacy.
- Dio Chrysostom is banished from Rome, Italy, and Bithynia after advising one of the Emperor's conspiring relatives.
- Domitian levies Legio I Minervia.
- Possible date of the Battle of Mons Graupius (83 or 84). According to Tacitus, 10,000 Britons and 360 Romans are killed.
- Roman emperorDomitian fights the Chatti, a Germanic tribe. His victory allows the construction of fortifications (Limes) along the Rhine-frontier.
- Inchtuthil, Roman fort built in Scotland.
- Domitian is again additionally a Roman Consul.
- Possible date that Demetrius of Tarsus visited an island in the Hebrides populated by holy men, possibly druids.
- In Rome, the castration of slaves is prohibited.
- Possible date of the Battle of Mons Graupius (83 or 84), in which Gnaeus Julius Agricola defeats the Caledonians.
- Emperor Domitian recalls Agricola back to Rome, where he's rewarded with a triumph and the governorship of the Roman province Africa, but he declines it.
- Pliny the Younger is sevir equitum Romanorum (commander of a cavalry squadron).
- The construction of the Limes, a line of Roman fortifications from the Rhine to the Danube, is begun.
- Through his election as consul for ten years and censor for life, Domitian openly subordinates the republican aspect of the state to the monarchical.
- Domitian increases the troops' pay by one third, thus securing their loyalty.
- Dacians under Decebalus engage in two wars against the Romans from this year to 88 or 89.
- Emperor Domitian repulses a Dacian invasion of Moesia.
- Domitian appoints himself censor for life, which gives him the right to control the Senate. His totalitarian tendencies put the senatorial aristocracy firmly in opposition to him.
- Baekje invades the outskirts of Silla in the Korean peninsula. The war continues till the peace treaty of 105.
- Emperor Domitian introduces the Capitoline Games.
- The Roman General Trajan, future emperor, begins a campaign to crush an uprising in Germany.
- Germany is divided into two provinces, Upper Germany and Lower Germany.
- Roman legions face disaster in Dacia in the First Battle of Tapae, when Cornelius Fuscus, Praetorian prefect, launches a powerful offensive that becomes a failure. Encircled in the valley of Timi, he dies along with his entire army. Rome must pay tribute to the Dacians in exchange for a vague recognition of Rome's importance.
- The Roman Maternus arrives in Ethiopia.
- Lyon, a city in Gaul, has a population of over 100,000.
- Sextus gains power in the senate.
- Two Egyptian obelisks are erected in Benevento in front of the Temple of Isis, in honour of emperor Domitian.
- Quintilian retires from teaching and from pleading, to compose his great work on the training of the orator (Institutio Oratoria).
- The First Dacian War ends: Decebalus becomes a client king of Rome, he receives money, craftsmen and war machines to protect the borders (Limes) of the Roman Empire.
- Emperor Han Zhangdi dies at age 31 after a 13-year reign in which Chinese military forces have become powerful enough to march against tribes who threaten their northern and western borders. Having used intrigue as well as armed might to achieve his ends. Zhangdi and his General Ban Chao have reestablished Chinese influence in Inner Asia, but court eunuchs have increased their power throughout the emperor's reign. Zhangdi is succeeded by his 9-year old son Zhao, who'll reign until 105 as emperor Han Hedi, but he'll be a virtual pawn of Empress Dou (adoptive mother) and scheming courtiers who'll effectively rule the Chinese Empire.
- Last year (4th) of yuanhe era and start of zhanghe era of the Chinese Eastern Han Dynasty.
- Legio XIII Gemina is transferred to Dacia to help in the war against Decebalus.
- Aquincum (old Budapest, Óbuda) is founded.
- First year of Yongyuan era of the Chinese Han Dynasty.
- June – The Han Chinese army under Dou Xian (d. 92), allied with the southern Xiongnu, is victorious over the Northern Xiongnu in the Battle of Ikh Bayan.
- Change of Patriarch of Constantinople from Polycarpus to Plutarch.
- Publication in Syria or Phoenicia of the Gospel of Matthew by a converted Jewish scholar.
- Titus Aurelius Fulvus Boionius Arrius Antoninus, better known as Antoninus Pius. Born in 86, he would eventually become a Roman emperor.