The oldest settlement in the area was Ouderkerk aan de Amstel, which dated from the 11th century (and thus is older than Amsterdam).
Meanwhile, when a dam was constructed at the mouth of the Amstel, the now strategically located fishing hamlet in the north of Nieuwer-Amstel grew quickly.
On 1 January 1811 Amstelland was integrated into a new département called Zuyderzee (Zuyderzée), with van Styrum remaining in office until 11 February 1811.
Today Amsterdam and Amstelveen have grown extensively, including large parts of land on both sides of the river.
The term Amstelland nowadays generally refers to the area along the river Amstel just south of the city of Amsterdam.
Extending south of the Utrechtsebrug, this green area has a rural character and remains free of development.
When used in this sense, Amstelland means just the triangle of green space just south of Amsterdam and does not include the surrounding built-up areas and villages.