In 1579, the union of seven provinces of the northern Netherlands Holland, Zeeland, Friesland, Groningen, Utrecht, Gelderland, and Overijssel that, as the United Provinces, became the basis of opposition to the Spanish crown and the foundation of the present-day Dutch state.
The emblem reflects the Vatican's importance as the headquarters of the Roman Catholic Church. The colours of the flag are based on the gold and silver of the papal keys. Effective date: 8 June 1929.