Afonso was the son of Teresa, the illegitimate daughter of King Alfonso VI of León and Castile, and her husband, Henry of Burgundy. According to Fernão Lopes' "Crónica de Portugal de 1419," the future Portuguese king was born in Guimarães, which was at the time the most important political center of his parents. This was accepted by most Portuguese scholarship until in 1990 Torquato de Sousa Soares proposed Coimbra, the center of the county of Coimbra and another political center of Afonso's progenitors, as his birthplace, which caused outrage in Guimarães and a polemic between this historian and José Hermano Saraiva. Almeida Fernandes later proposed Viseu as the birthplace of Afonso basing himself on the "Chronica Gothorum", which states Afonso was born in 1109, a position followed by José Mattoso in his biography of the king. Abel Estefânio has suggested a different date and thesis, proposing 1106 as the birth date and the region of Tierra de Campos or even Sahagún as likely birth places based on the known itineraries of counts Henry and Teresa.