The ruling dynasty of Portugal (1640–1910). Alfonso, an illegitimate son of John I of Portugal, was made first Duke of Braganza (1442). His descendants became the wealthiest nobles in the kingdom and, by marriage into the royal family, had a claim to the Portuguese throne before the Spaniards took control of the country in 1580. When the Portuguese threw off Spanish rule in 1640, the 8th Duke of Braganza ascended the throne as John IV. The title of Duke of Braganza was thenceforth borne by the heir to the throne.