Portuguese nobility

Portuguese nobility was the class of legally privileged and titled persons (nobility) acknowledged by the Kingdom of Portugal. During the absolute monarchy, nobles enjoyed the most privileged status and held the most important offices after members of the ruling dynasty and major hierarchs of the Roman Catholic Church.

With the introduction of the constitutional monarchy in 1834, the influence of nobles substantially decreased, although the erosion of their power had begun to accelerate from the time of the prime minister, the Marquês de Pombal, in the mid-18th century.

After Portugal became a republic in 1910, some descendants of the nobility continued to bear their families' titles according to standards sustained by the Portuguese Institute of Nobility (Instituto da Nobreza Portuguesa), headed honorarily by Duarte Pio, Duke of Braganza, the pretender to the Portuguese Crown.

Portuguese nobility could be traced to the reign of Alfonso VI of Leon, whose reign saw the sons of Leonese nobility become established as gentry in the north of Portugal, between the Minho River and the Douro River. This was the region of the sun and the most powerful men of the kingdom. They united nobility of birth to the authority and prestige of public office.

They were followed in the hierarchy, in descending order, by infancies, cavaleiros (knights) and escudeiros (squires). A title of Spanish origin, filho de alguém, applied to senior functionaries and gave rise to the word fidalgo, who, in the 14th century, became widespread and went on to name all of noble lineage, thereby designating the highest class of the nobility, without distinction of rank.

...
Wikipedia