312
312 was a leap year.
| Millennium: | 1st millennium |
|---|---|
| Centuries: | 3rd century – 4th century – 5th century |
| Decades: | 280s 290s 300s – 310s – 320s 330s 340s |
| Years: | 309 310 311 – 312 – 313 314 315 |
Events
- October 28 – Battle of Milvian Bridge: Constantine I defeats Maxentius and becomes the only Roman Emperor in the West.
- Construction of the Arch of Constantine in Rome begun.