The 3rd century is defined by the calendar of Earth as occurring from the year 201 through the year 300.
- Spock's ancestors adopt a ceremonial ground that remains in their family at least until the 23rd century. (TOS: "Amok Time")
- The society on planet 892-IV evolves on a path similar to that of Earth's Roman Empire, in an example of Hodgkin's Law of Parallel Planetary Development. (TOS: "Bread and Circuses")
|2nd century||Timeline||4th century|