Union of Utrecht

The Union of Utrecht (Dutch: Unie van Utrecht) was a treaty signed on 23 January 1579 in Utrecht, the Netherlands, unifying the northern provinces of the Netherlands, until then under the control of Habsburg Spain.

The Union of Utrecht is regarded as the foundation of the Republic of the Seven United Provinces, which was not recognized by the Spanish Empire until the Twelve Years' Truce in 1609.

The treaty was signed on 23 January by Holland, Zeeland, Utrecht (but not all of Utrecht) and the province (but not the city) of Groningen. The treaty was a reaction of the Protestant provinces to the 1579 Union of Arras (Dutch: Unie van Atrecht), in which the southern provinces declared their support for Roman Catholic Spain.

During the following months of 1579, other states signed the treaty as well, such as Ghent, cities from Friesland, as well as three of the quarters of Guelders. In the summer of 1579, Amersfoort from the province of Utrecht also joined, together with Ypres, Antwerp, Breda and Brussels. In February 1580, Lier, Bruges and the surrounding area also signed the Union. The city of Groningen shifted in favor under influence of the stadtholder for Friesland, George van Rennenberg, and also signed the treaty. Later on, Zutphen also signed so Guelders (of which Zutphen is one of the quarters) supported the Union completely. This happened in April 1580, as did the signing of Overijssel and Drenthe.

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