Which kingdom was in power when the portuguese arrived?

The Portuguese Empire (Portuguese: Império Português), also known as the Portuguese Overseas (Ultramar Português) or the Portuguese Colonial Empire (Império Colonial Português), was one of the largest and longest-lived empires in world history and the first colonial empire of the Renaissance. It existed for almost six centuries from the capture of Ceuta in 1415 to the handover of Portuguese Macau to China in 1999.

The first era of the Portuguese empire originated at the beginning of the Age of Discovery. Initiated by the Kingdom of Portugal, it would eventually expand across the globe. Portuguese sailors began exploring the coast of Africa and the Atlantic archipelagos in 1418-19, using recent developments in navigation, cartography and maritime technology such as the caravel, in order that they might find a sea route to the source of the lucrative spice trade. In 1488, Bartolomeu Dias rounded the Cape of Good Hope, and in 1498, Vasco da Gama reached India. In 1500, either by an accidental landfall or by the crown's secret design, Pedro Álvares Cabral discovered Brazil on the South American coast.

Over the following decades, Portuguese sailors continued to explore the coasts and islands of East Asia, establishing forts and factories as they went. By 1571, a string of naval outposts connected Lisbon to Nagasaki along the coasts of Africa, the Middle East, India and South Asia. This commercial network and the colonial trade had a substantial positive impact on Portuguese economic growth (1500-1800), when it accounted for about a fifth of Portugal's per capita income.

When Philip II of Spain, I of Portugal, inherited the Portuguese crown in 1580, this began a 60-year union between Spain and Portugal that has since been given the historiographic term of the Iberian Union. Though the realms continued to be administered separately, the Council of Portugal ruled the country and its empire from Madrid. As the King of Spain was also King of Portugal, Portuguese colonies became the subject of attacks by three rival European powers hostile to Spain: the Dutch Republic, England, and France. With its smaller population, Portugal was unable to effectively defend its overstretched network of trading posts, and the empire began a long and gradual decline. Eventually, Brazil became the most valuable colony of the second era until, as part of the wave of independence movements that swept the Americas during the early 19th century, it broke away in 1822.

The third era represents the final stage of Portuguese colonialism after the decolonization of the Americas of the 1820s. The colonial possessions had been reduced to the African coastline (expanded inland during the Scramble for Africa in the late 19th century), Portuguese Timor, and enclaves in India (Goa) and China (Macau). The disastrous 1890 British Ultimatum led to the contraction of Portuguese ambitions in Africa.

Under António Salazar, the Second Portuguese Republic made some ill-fated attempts to hold on to its last remaining colonies and overseas provinces after the 1961 Indian annexation of Goa, embarking on the Portuguese Colonial War in Africa which lasted until the final overthrow of the regime in the Carnation Revolution of 1974. Macau was returned to China in 1999.