Berengaria was first cousin to Queen Berengaria of England, wife of Richard the Lion-hearted. Both of the Princess Beregarias were named after their grandfather Count Berenguer of Barcelona. Princess Berengaria was introduced to King Valdemar through his sister, Ingeborg, the wife of King Phillip Auguste of France, another of her cousins. Berengaria was the youngest daughter of King Sancho I of Portugal. Valdemar’s first wife, Princess Margrethe of Bohemia, later known as Dronning Dagmar Queen Dagmar, had been immensely popular, blond and with Nordic looks. Queen Berengaria was the opposite, dark-eyed, raven haired, yet a beauty in her own right. The Danes made up folk songs about the beautiful new queen and blamed her for the high taxes Valdemar levied, although the taxes went to his war efforts, not just to his Queen. The Danes still grieved over the kind-hearted Queen Dagmar, so that it wasn't easy for the new queen from Portugal to win good-will with her husband's Danish subjects.
During his years as married to Queen Berengaria, in 1219, Valdemar went on a victorious campaign to Estonia, during which legend has it that the Danish flag first appeared, falling from the heavens, inspiring victory for the Danish forces.
Queen Berengaria, after giving birth to three future kings, died in childbirth in 1221, in her 31st year. Queen Berengaria is buried in Saint Bendt's Church in Ringsted, Denmark, on one side of Valdemar II, with Queen Dagmar buried on the other side of the King.