Updated: Jun 22, 2021
Today in 1579 a treaty was signed by Holland, Zeeland, Utrecht, and the province (but not the city) of Groningen which effectively split the Netherlands into a Protestant North and Catholic South. Obviously it is a little more complicated than that and may be more about respecting religious freedom than forming a Protestant Republic. This became known as the Treaty of Utrecht. Listen to see what you think...
Today a treaty was signed by Holland, Zeeland, Utrecht, and the province (but not the city) of Groningen. This became known as the Union of Utrecht and effectively united the northern provinces of the Netherlands, until then under the control of Habsburg Spain. Some historians have described this as the formation of a Protestant Republic as it was a reaction to earlier Union of Arras in which two southern provinces and a city had declared their support for Catholic Spain. However, it was more expansive than a Protestant republic in that the Union of Utrecht allowed complete freedom of religion and was thus one of the first unlimited edicts of religious toleration. An additional declaration allowed provinces and cities that wished to remain Roman Catholic to join them. During the following months, other states signed the treaty as well, such as Ghent, cities from Friesland, as well as three of the quarters of Guelders, then a bit later in the summer, 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. Antwerp was the capital of the union until its fall to the Spanish. Flanders was almost entirely conquered by the Spanish troops, as was half of Brabant. The United Provinces still recognized Spanish rule after the Union of Utrecht. However, the Union contributed to the deterioration in the relationship between the provinces and their lord, and two years later the United Provinces declared their independence of the king in the Act of Abjuration.
The Eighty Years' War (sometimes known as the Dutch War of Independence) had started 11 years before in 1568 and had been a revolt of the Seventeen Provinces of what are today the Netherlands, Belgium, and Luxembourg against Spain. After the initial stages, Philip had regained control over most of the rebelling provinces. However, the northern provinces continued their resistance. They eventually were able to oust the Habsburg armies, and in 1581 they established the Republic of the Seven United Netherlands. Here we see the origins of the Dutch colonial empire, which began with Dutch attacks on Portugal's overseas territories. The protracted conflict ultimately cost Spain the Dutch provinces. The dominant reason was that the Spanish were over-extended and could no longer afford the expense of the conflict. This was not the case in the Netherlands, its booming economy, mainly powered by Dutch banks and a thriving stock market, meant that the soldiers in the rebel armies got their pay on time. On the Spanish front it was very different, troops were usually owed months and in many cases years of back pay and, as a result, fought with less enthusiasm and often mutinied . It was the waning of the Spanish ‘Siglo de Oro’ its golden period of overseas expansion and European power. The Dutch Republic was eventually recognized by Spain and the major European powers in 1609 at the start of the Twelve Years' Truce. Then after more fighting, the Dutch Republic was definitively recognised as an independent country no longer part of the Holy Roman Empire and ushered in the beginning of the Dutch Golden Age. Although religion had lit the touchpaper, it hads significant economic and geopolitical effects, and the Spanish Empire lost its European hegemonic status. The success of the Dutch Republic in its struggle to get away from the Spanish Crown had damaged Spain's Reputatión, and had significant effects on its colonies. Jesuit father Diego de Rosales described Chile from a military point of view as "Indian Flanders". As the Dutch grew as a geopolitical force, in a couple of generations William III of Orange would invade England 1688, albeit assisted by his wife Mary II to depose her father James II of England, Scotland and Ireland, and his replacement by his daughter and her Dutch husband. A staunch Protestant, he also imported to Britain the Dutch tolerance for religious freedom with the Toleration Act 1689 bringing peace to, nonconformists (see the Pod of Jan 21 about the Pilgrim Fathers) It did not, however, extend toleration as far as William wished, still restricting the religious liberty of Roman Catholics, non-trinitarians, and those of non-Christian faiths