Decades: 300s BC 290s BC 280s BC 270s BC 260s BC - **250s BC** - 240s BC 230s BC 220s BC 210s BC 200s BC

Years: 263 BC 262 BC 261 BC 260 BC 259 BC - **258 BC** - 257 BC 256 BC 255 BC 254 BC 253 BC

- Battle of Cos: Naval victory of Antiochus II Theos over Ptolemy II