Utrecht, Union of

a military and political union concluded Jan. 23, 1579, in Utrecht by five provinces of the northern Netherlands, namely, Holland, Zeeland, Utrecht, Gelderland, and Groningen. The provinces of Overijssel and Friesland joined the union a short time later.

The union was formed against Spain, which was attempting to reestablish the supremacy in the Netherlands that it had virtually lost during the Netherlands bourgeois revolution of the 16th century. The union was also intended to counter internal feudal Catholic reaction, as exemplified by the action of the southern provinces in concluding the counterrevolutionary Union of Arras on Jan. 7, 1579.

The Union of Utrecht provided for the indissoluble union of the provinces, the creation of a combined army and the concerted waging of the revolutionary war, the implementation of a common foreign policy, and the establishment of a single monetary system. Although it did not formally declare the deposition of the Spanish king, the union left no room for effective royal power. It provided for a federal political system. The union laid the foundation for the independent political existence of the republic of the United Provinces. Many cities in Flanders and Brabant also joined the union, but in the 1580’s they were conquered by Spanish troops.