Centuries: 4th century BC - 3rd century BC - 2nd century BC
Decades: 290s BC 280s BC 270s BC 260s BC 250s BC - 240s BC - 230s BC 220s BC 210s BC 200s BC 190s BC
Years: 251 BC 250 BC 249 BC 248 BC 247 BC - 246 BC - 245 BC 244 BC 243 BC 242 BC 241 BC
- In Rome, the number of praetors is increased from one to two
- Ying Zheng, the later "first emperor" (Qin Shi Huang Di), becomes King the Qin Dynasty of China.
- Seleucus II Callinicus becomes King of the Seleucid dynasty.
- Ptolemy III becomes King of Egypt.
- Queen Arsinoe III of Egypt of the Ptolemaic Dynasty (or 245 BC).
- Ptolemy II, king of Egypt.
- Antiochus II Theos, King of the Seleucid dynasty.