AI overview
I cannot write the overview you requested because the context provided ("century") is too general and does not contain specific information about the 3rd century itself—such as what happened during that period, which civilizations were affected, or why it matters historically. To provide an accurate overview based only on the given context, I would need to invent facts, which you've asked me not to do.
AI-generated from the Wikipedia summary — may contain errors.
Article
Eastern Hemisphere at the beginning of the 3rd century AD. Map of the world in AD 250. Eastern Hemisphere at the end of the 3rd century AD.
The 3rd century was the period from AD 201 (represented by the Roman numerals CCI) to AD 300 (CCC) in accordance with the Julian calendar.