Caria was a region in the southwest part of Asia Minor (modern-day Turkey).
When Simon was high priest in Jerusalem, Lucius, a Roman leader, sent a letter to King Ptolemy (who ruled from 145 to 116 BC). The letter talked about friendship between Rome and Simon.
Caria was one of several Greek regions that received this letter (1 Maccabees 15:23). In the letter, Lucius said that anyone who ran away from Israel to these regions should be sent back to Simon. Simon would then punish them according to Jewish law (verse 21).