Infanta Teresa, Countess of Flanders

Infanta Teresa of Portugal (pron. IPA2|tɨ'ɾezɐ or [IPA|'tɾezɐ] ) was a Portuguese infanta, being the third daughter of Portuguese 1st King Afonso Henriques and Maud of Savoy. She was born c. 1157 and died in 1218 in Veurne, Flanders.

Around 1183 she married Philip of Alsace, Count of Flanders, becoming Countess consort of Flanders. Because of the difficulty of pronouncing her name, she changed it to Matilde (Matilda or Mahaut).

Her marriage was celebrated (in the Tournai Cathedral, Bruges) after the death of Elisabeth of Vermandois, first wife of Philip, who hadn't given him any children, and was because Philip needed an heir so that his county wouldn't fall into French hands. For its part, Portugal, a new-born country, managed to secure an important alliance with Flanders, and European recognition. Teresa brought a considerable dowry, something that helped Philip manage his war with France for a couple of more years, before making peace in 1186. A reasonable number of Portuguese immigrants (mainly merchants) also went to Flanders with the infanta.

Teresa lived in one of the most luxurious royal courts of Europe, in which Philip patronized Chrétien de Troyes, author of a famous cycle of Arthurian stories and one of the fathers of the Graal theme in literature.

However, like Elisabeth of Vermandois, Teresa never gave birth, and after Philip's death, the county went to his sister Margaret I, Countess of Flanders.

After Philip's death in August 1191, she would marry again, this time to Eudes III of Burgundy in 1193. She interceded favourably with the king of France, for the marriage of her nephew Infante Fernando of Portugal with her grand-niece Jeanne, Countess of Flanders. Her second marriage produced no children, and so, she ended up being repudiated by the Duke, so that he could marry Alice of Vergy.

She has been reported to be Afonso I of Portugal's favourite daughter. In a work by Portuguese historian Maria Roma, she is described as beautiful and as a "prideful woman with a vyril energy", of the fibre of her grandmother Teresa, Countess of Portugal.

She is tenderly celebrated in Bruges every year.