Soissons (French pronunciation: ​[swa.sɔ̃]) is a commune in the Aisne department in Picardy in northern France, located on the Aisne River, about 100 kilometres (62 mi) northeast of Paris. It is one of the most ancient towns of France, and is probably the ancient capital of the Suessiones. Soissons is also the see of an ancient Roman Catholic diocese, whose establishment dates from about 300.