An "S" in Marseille?

Another dimension of Marseille is flagged by the fact that Anglo-Saxons spell it with an "s" -- Marseilles. According to a local businessman I had once interviewed, the reason is because there are so many aspects to Marseille(s). It is a port city, a city of history and culture, an industrial power, and its port area and surroundings encompass the largest urban redevelopment project in Europe.