The Chronicon Regum Legionensium names (in order) "Urraca, Elvira and Afonso" as the children of Count Henrique & his wife. The year in which Afonso was born is uncertain. Barbosa quotes a document dated “XVII Kal Oct” in 1173 which records the transfer of the body of San Vicente which states “Regni autem regis Alfonsi 45 vitæ vero eiusdem 67”, which would place his birth in 1106, and another document dated “era 1222”  which records the death of “Rex Portugallensium doñus Alfonsus año vitæ suæ 78”. The former would place his birth in , and the latter in [1107/08] assuming that Alfonso´s death can be dated to 1185. Brandaõ quotes a breviary from Alcobaça which records the birth “era 1147”  of “Aldefonsus primus rex Portugaliæ, filius comitis Henrici”, a manuscript about the works of San Fulgencio which records events in “era 1186 ...37 ætatis annum et regni 19” [1110/11], and a historia dos Godos which records “era 1163  Infans Alfonsus Henrici comitis filius ætatis anno 14” . The Chronicon Lusitanum records the birth in 1151 (1113) of “Infans Alfonsus Comitis Henrici et Reginæ D. Tarasiæ filius, Regis D. Alfonsi nepos”, although a posthumous birth would probably have been noted. As can be seen, the full range of years from 1106 to 1112 is covered by these various contradictory sources. There appears no way of deciding which is more accurate than the others, although Brandaõ suggests that 1110 is correct.
He succeeded his father in 1112 as AFONSO I Conde de Portugal. "…Infanta dna Sancia, Infans dns Adefonsus regis consanguineus…" subscribed the charter dated 13 Nov 1127 under which King Alfonso VII donated "el castillo de San Jorge en la Sierra del Pindo" to Santiago de Compostela. It is probable that the second subscriber was Afonso de Portugal. Ruling through his mother, he overthrew and expelled her from Portugal in 1128. In 1135 he refused to swear homage to Alfonso VII King of Castile, from that time using the title 'Prince of Portugal'. He moved his capital to Coimbra. In 1139 he won a notable victory against the Muslims in Santarem who were reduced to tributary status.
He proclaimed himself AFONSO I "the Conqueror" King of Portugal in 1139. His establishment of the archbishopric of Braga gave Portugal ecclesiastical independence. “Alfonsus, Portugaliæ rex, comitis Henrici et reginæ Theresiæ filius, magni quoque regis Alfonsi nepos…cum uxore mea regina donna Malfada, filia comitis Amedei de Moriana” confirmed donations to La Charité-sur-Loire by his father by charter dated Jul 1145. He swore allegiance to the Pope, although Papal recognition of his title of king of Portugal was only given in 1179. He expanded his territory to the south, capturing Lisbon in 1147 with the help of a force of English, French and Flemish crusaders.
The De Rebus Hispaniæ of Rodericus Ximenes records that "Aldefonsus" was buried "Coimbræ in Monasterio S. Crucis". The Chronicon Conimbricensi records the death “VIII Id Dec” in  of “Rex Ildefonsus Portugalensis”. 1