In prehistoric times, the area was inhabited by the Salyens tribe, who were sheep farmers and salt traders. When the Romans arrived in 125 BC, they drained the swamps that existed and built a castle around which a small town emerged. During the Middle Ages, the village was known as la villa Sallonne and was under the protection of the Holy Roman Empire, hence the name of the (rebuilt by this stage) castle - Chateau de l'Emperi.
During the 15th century, Salon was ruled by the Counts of Provence and the town experienced an economic boom. Of course, much of this wealth was destroyed during the 16th century Wars of Religion, the cause of many a towns downfall in Provence.
It was however, at this time that Salon welcomed a historical figure inside its walls. The famous seer and writer Nostradamus made Salon his home in 1547, and it was here that he wrote his celebrated Prophecies. He died in 1566 and was buried in the local chapel before being re-interred in the Collegial Saint Laurent.
The 18th century was the start of Salon's industrial history, when the manufacture of silks became established. Later in the 19th century, focus switched to the manufacture of soaps and oils, and Salon developed as a trading centre. The accumulating wealth was used to create boulevards and build grand mansions, including the town hall.
Salon de Provence suffered a serious earthquake in 1909 which caused some damage to some of the town's most iconic buildings.