The founding royal dynasty of Portugal, which won independence under Afonso I and ruled until the succession crisis of 1383–85.
The line began with Henry of Burgundy, a French noble who around 1096 married Teresa, illegitimate daughter of Alfonso VI of León-Castile, and received the County of Portugal as a frontier fief. Their son Afonso Henriques rebelled against his mother, defeating her faction at the Battle of São Mamede in 1128 and asserting his own rule.
Afonso pushed south against the Moors, and after his victory at the Battle of Ourique in 1139 he took the title of king. The Treaty of Zamora in 1143 won León’s recognition, and papal acknowledgement in 1179 confirmed Portugal as an independent kingdom.
Afonso I and his son Sancho I drove the Reconquista down the Atlantic coast; the capture of Lisbon in the Siege of Lisbon of 1147, with the help of northern crusaders, was the decisive step. Sancho I earned the name "the Populator" for founding towns, granting charters, and settling the reconquered lands.
The early Afonsine kings had to build a state as well as conquer one — organising a frontier society of townsmen, military orders, and a fractious nobility into a working kingdom.
Afonso II turned from conquest to government, issuing Portugal’s first written laws and asserting royal rights against the Church and the great nobles. That conflict sharpened under Sancho II, whose reign collapsed into civil war and who was deposed in 1248 in favour of his brother Afonso III.
Afonso III completed the Reconquista by taking the Algarve, summoned the first Portuguese Cortes to include townsmen, and moved the kingdom’s centre of gravity toward Lisbon.
King Dinis, the "Farmer King", encouraged agriculture, planted the Leiria pine forest that later built Portugal’s ships, founded the university that became Coimbra in 1290, and made Portuguese rather than Latin the language of the royal chancery. He reorganised the Templars’ Portuguese assets into the new Order of Christ.
His successors ruled a settled kingdom. Afonso IV fought beside Castile against the Moors at the Salado in 1340, but his reign is best remembered for the tragedy of Inês de Castro, mistress of his son Pedro, whom the king had killed.
Pedro I ruled as a stern justiciar, and legend told that he had the murdered Inês de Castro exhumed and honoured as queen. His legitimate son Ferdinand I entangled Portugal in the wars of Castile and married his daughter Beatrice to the Castilian king.
When Ferdinand died in 1383 without a son, that marriage threatened to absorb Portugal into Castile. The resulting 1383–85 crisis ended with the Portuguese victory at the Battle of Aljubarrota in 1385 and the accession of John I, Pedro’s illegitimate son, founding the House of Aviz and preserving Portuguese independence.