The conquest of Portucale in 868 by Vímara Peres, a warrior of Alfonso III of Leon, is considered a turning point in the history of Porto. Since the second half of the 6th century, during the time of the Suevi, the settlement of Portucale in Castro Novo had been the seat of the Portucalense Diocese, but after 868 it increased in importance: it became the centre for the reconquest and unification of surrounding territories which, by the mid-10th century, formed the Portugalensis province. It was during this period that the first signs of a sense of nationality arose among its inhabitants, known as Portugalenses. It was Portucale that therefore gave its name to the Portuguese nation!
In 1120, Teresa, the widow of Count Henry, granted Bishop Hugo and his successors the small burgo of Porto and land (couto), to which the Bishop granted a charter in 1123. Their boundaries were later confirmed and extended by King Afonso Henriques. In 1147, the northern European crusaders setting off on the Second Crusade to the Holy Land sailed into the Douro and the bishop of Porto, Pedro Pitões, preached an eloquent sermon to them on Crasto of Portucale, the hill opposite the Cathedral, exhorting them to help Afonso Henriques capture Lisbon. The bishop then joined the fleet and took part in the attack. After Lisbon was taken, Porto began to flourish: its population and economic importance grew and the burghers involved themselves in disputes and conflicts with the Porto bishopric. Two centuries later, João I finally put an end to these conflicts, granting the bishops of Porto temporal jurisdiction over the burgo and its land. During the 1383-1385 crisis and civil war, Porto served and supported the Master of Aviz, who claimed to be Regedor and Defender of Portugal against the Castilians, for which reason the city received the title of MUI NOBRE E SEMPRE LEAL CIDADE (most noble and ever loyal city).
This was followed by the cycle of overseas conquests and discoveries. Just as the warriors who conquered the south from the Moors had come from the north, likewise the north, where Henry the Navigator and so many sailors were born, was the driving force behind the great maritime voyages. In the 15th century, Porto was one of the cities where most ships were built and from where most sailors set sail.
During the Spanish occupation (1580-1640), the city continued to change, developing in size and in its form of administration. After the restoration of independence, Porto began to reach its economic peak, with a period of maximum vitality in the 18th century. This was essentially derived from the Douro wine trade and from the city’s busy sea port. Trading with Portuguese colonies and, above all, with Great Britain intensified. The Baroque flourished in these circumstances, boosted by gold from Brazil, attracting a considerable number of foreigners to the city. The city was transformed and modernised, adopting the fashions and aesthetics of a refined Baroque and becoming a source of inspiration for other regions in north-west Portugal.
In the second half of the 18th century, Porto, which had become an extraordinarily wealthy city, grew and developed on a monumental scale, the old medieval town being radically transformed by the urban reforms of João de Almada e Melo (1757-1786), with buildings in the neo-classical (neo-Palladian) style, under the influence of its English residents. Secular buildings on a monumental scale only previously seen in religious architecture, as well as hospitals, theatres, barracks and prisons began to appear in the urban landscape of Porto.
The turbulence of the 19th century in Portugal as a whole- the French invasions and the liberal wars - was reflected in the city. In the first case, Porto revolted in 1808 against the troops of General Junot, resulting in retaliations and the invasion by Soult in the following year. In the second case, the city played a decisive role in the victory of the liberal cause, defending itself against absolutist raids and supporting the defenders of the constitution. As a result of this action, Pedro IV gave it the title “MUI NOBRE, INVICTA E SEMPRE LEAL CIDADE DO PORTO” (most noble, unvanquished and ever loyal city of Porto).
Life in the city reflected the internal and external political changes that took place between 1822 and the establishment of the Republic in 1910, with obvious effects on the country's economy and society. Mouzinho da Silveira’s law of 1835 led to a new administrative division of the country, with the extinction of certain parishes. The Administrative Code of 1878 resulted in further changes – districts were created, divided into municipalities which were in turn divided into parishes. Porto became the capital of a district and a municipality. Like much of the country, the city suffered following the financial crisis of 1891. This was also the year in which the defenders of the republicanism, led by the Republican Party, rose up in Porto, in what became known as the Revolt of 31 January.
The early years of the 20th century were politically agitated and the dictatorship of João Franco resulted in the regicide (1 February 1908). Porto, which had long embraced Republican ideals, supported the establishment of the Republic on 5 October 1910. After the founding of the Republic, the city experienced new reforms, including the construction of Avenida dos Aliados, a project launched in 1915, by the Englishman Barry Parker, and which was continued under the influence of the French school by the architect Marques da Silva, who had studied in Paris. This plan was followed by others between 1914 and 1962, interventions that were not always completed, but which reflected a constant concern to regulate, discipline and improve the city. This living fabric continues to be regenerated through the classification of certain buildings, beginning in the 20th century; demolitions and the construction of new buildings; through private initiative or public policy, resulting in a city that has been adapted to new ways of living.