I want to know the answer to the following question:
When did Massalia side with Pompey?
All the background I'm provided with is that "The Hellenistic period saw the Greek alphabet spread into southern Gaul from Massalia (3rd and 2nd centuries BCE) and according to Strabo, Massalia was also a center of education, where Celts went to learn Greek.". Is that enough to answer the question?