Netherlands-Indonesia Union

The Netherlands-Indonesia Union (Dutch: Nederlands-Indonesische Unie, NIU; Indonesian: Uni Indonesia–Belanda, UIB), also called the two-state solution (Dutch: tweestaten-oplossing) by the Dutch, was a confederal relationship between the Netherlands and Indonesia that existed between 1949 and 1956. Agreed in 1949, it was an attempt by the Netherlands to continue to bind its former colony of the Dutch East Indies (now Indonesia) to the Netherlands in a confederal manner, at least within the framework of a personal union, even after independence had been granted.

Source: Wikipedia — Netherlands-Indonesia Union (CC BY-SA 4.0)