D. Afonso Henriques was the son of the counts D. Henrique – second son of Henrique, Duke of Burgundy – and D. Teresa, the illegitimate daughter of the king of León and Castile, Afonso VI. He was born in 1109, probably in Viseu, as it is in this city of Beira that, at that time, the presence of his mother, the Infanta D. Teresa, can be historically determined, taking into account the reconstruction of her itinerary based on the documentary sources of the time. The future king was educated in Entre Douro e Minho, in his master’s lands, possibly D. Egas Moniz de Ribadouro. Orphaned by father in 1112, so at the age of 3, he certainly could not keep any other memories than the memories reported by his educators. The mother’s subsequent marriage to the Galician noble Fernão Peres de Trava, and the attempt by the new court of D. Teresa to attract Portuguese territory back to Galician orbit, are factors that would certainly have contributed to remove Afonso Henriques from his mother’s conviviality.
D. Afonso Henriques defeated the anti-patriotic forces led by his mother’s lover, Fernão Peres de Trava at the battle of São Mamede, in 1128, inaugurating the first of four dynasties of kings in Portugal, symbols of the nation until the beginning of 20th century. Interestingly, it is known today that the nationalist propaganda of the 20th century turned her husband into a lover to diminish the figure of the Galician count.
On the 25th of July 1139, he won against Islam the most emblematic of his victories, in the battle of Ourique, mythified by the later historiography in an elaborate legend.
In 1144, Pope Eugénio III called for a new crusade for the Iberian Peninsula. The armada arrived in the city of Porto on June 16, being convinced by the bishop of Porto, Pedro II Pitões, to take part in this military operation. After the conquest of Santarém (1147), knowing the availability of the Crusaders to help, D. Afonso Henriques’ forces continued southwards, over Lisbon.
The Siege of Lisbon began on July 1, 1147 and lasted until October 21, culminating in the conquest of this city from the Moors with the help of the Crusaders who were heading for the Middle East, more specifically for the Holy Land. It was the only success of the Second Crusade.The Portuguese forces advanced by land, those of the Crusaders by sea, penetrating the mouth of the Tagus River; in June of that same year, both forces were reunited, the first skirmishes were wounded on the outskirts west of the hill on which the city of then, today called Baixa, stood. After violent fighting, both this area and the east were dominated by Christians, thus imposing a siege on the opulent mercantile city.
Well defended, the city walls proved impregnable. The weeks passed in sorties of the besieged ones, while the besiegers’ war machines launched all sorts of projectiles at the defenders, the number of dead and wounded increasing from side to side.
In early October they opened a breach where the besiegers launched themselves. On the verge of a Christian assault on two fronts, Muslims, weakened by skirmishes, hunger and disease, capitulated on 20 October.
But as often happens, in this part of history, a legend took the place of reality: the legend says that D. Afonso Henriques had laid siege to the city of Lisbon, helped by the many crusaders who passed through there on the way to the Holy Land.
In one of the attempts to assault one of the city gates, a knight from his army, Martim Moniz, faced the Moors and managed to keep the door open. His body was crossed between the two doors and allowed the Christians to enter the city.
Severely wounded, Martim Moniz entered the city with his companions and also made some victims among his enemies, before falling dead.
D. Afonso Henriques wanted to honor his courage and sacrifice, so he ordered that entrance to be named Martim Moniz.