In the year AD
- Roman Emperor Marcus Aurelius personally leads his legions in a campaign to chastise the Quadi tribe in what is now Hungary and Slovakia. He is accompanied by his attractive wife Faustina the Younger, who is adored by the soldiers and affectionately known as MATRI CASTRORVM, or "Mother of the Camp."
- Roman troops in Egypt put down a rebellion in the city of Tanis, leveling the once proud capital of the ancient Tanite kings of Egypt.
- Anti-Christian writer Celsus writes The True Word, a polemic attacking Christians for being secretive, reclusive, and disloyal to the Roman Empire.
- An entry for the year 174 in the Samguk Sagi, a Korean historical chronicle complied in 1145, records the earliest known reference to the phenomenon known to modern climatologists as "Asian Dust," in which massive dust clouds blow south and east from the Gobi Desert.
- The Odeum of Herodes Atticus, a massive theater at the base of the Acropolis in Athens capable of holding 2,500 spectators is constructed.
These people were born in 174:
- Chinese statesman Zhuge Jin, a minister of the Kingdom of Wu and the older brother of the famous Shu military strategist Zhuge Liang.
These people died in 174:
173 - 174 - 175