A little history of Notre-Dame-de-la-Seds church
This is Aix's first church. In the beginning, it was a small oratory founded by saint Maximin in the 4th century, upon a temple dedicated to Cybel.
The bishopric seat then moved near the new cathedral dedicated to Virgin Mary.
That was why they called it "Our-Lady-of-the-Seds", Seds for sedes episcopali, "bishop seat" in Latin!