Union of Utrecht Union of Utrecht The Union of 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
Flag of Utrecht (province) flag to represent the province. Flag of Utrecht (province) The flag of Utrecht () has been in use since 1952. It consists of two horizontal stripes of equal width, the upper one white and the lower one red. Similar to the flag of Poland or an upside-down flag of Monaco. In the top left corner of the flag there is a red square with a white cross. The flag originates from two other flags, one part of the Archdiocese of Utrecht, and the other of the (territorial) Archbishopric of Utrecht. In 1951 the province was advised by the Hoge Raad