Iberian Union
Throughout the 17th century, the increasing predations and surrounding of Portuguese trading posts in the East by the Dutch, English and French, and their rapidly growing intrusion into the Atlantic slave trade, undermined Portugal's near monopoly on the lucrative oceanic spice and slave trades. This sent the Portuguese spice trade into a long decline. To a lesser extent the diversion of wealth from Portugal by the Habsburg monarchy to help support the Catholic side of the Thirty Years' War, also created strains within the union, although Portugal did benefit from Spanish military power in helping to retain Brazil and in disrupting Dutch trade. These events, and those that occurred at the end of Aviz dynasty and the period of Iberian Union, led Portugal to a state of dependency on its colonies, first India and then Brazil.