Schiedam was founded in roughly the same way as its big neighbour Rotterdam: around the year 1230 the river Schie was dammedby the Lord of Wassenaer and the Amtlord Dirk Bokel of the Amt Mathenesse, this to protect the existing polderland against the seawater from the North Sea. In 1247, Lady Adelaide of Holland married John I, Count of Hainaut. As dowry she received from him the eastern part of the dam together with the adjacent polder. The dam attracted many trade activities because goods for and from the hinterland (Delft, and further away Leiden and Haarlem) had to be transhipped. A small town developed swiftly around the dam and its activities. In the year 1275 Schiedam received city rights from Lady Adelaide, this in her capacity as sister of William II, the reigning Count of Holland and becoming King of the Romans. She ordered the building of a castle near the Schie, which is known till today as the "Huis te Riviere" or "Slot Mathenesse" (English: "Castle Mathenesse"). Remnants of a donjon, which were once part of the castle, are still visible today in the centre of Schiedam and near the city office.
As a young settlement Schiedam soon got competition from surrounding towns and cities: in 1340, Rotterdam and Delft also were allowed to establish a connection between the Schie and the Meuse. From the 15th century on the city flourished as a place of pilgrimage on the devotion around Saint Lidwina, one of the most famous Dutch saints who lived her life in Schiedam. The city gained subsequently significance by fishing for herring. In 1428 a great city fire swept through Schiedam, thereby destroying large parts of the then wooden city .
The 18th century was Schiedam's Golden Age, when the gin industry flourished. The standstill drink imports from France made the emergence of the Schiedamse distillery possible. From dozens of distilleries Schiedam jenever was exported throughout the world. The Gin industry gave the city its nickname 'Black Nazareth'
