Beatrice of Falkenburg (c. 1254 – 17 October 1277), also referred to as Beatrix of Valkenburg, was the third spouse of Richard of Cornwall, and as such nominally queen of the Romans. She was 15 years old when she married the 60-year-old English prince, who proved to be a very devoted husband. In spite of the difference in their ages, Beatrice survived him by only five years, dying in England aged 23.
One of several children of count Theodoric II of Falkenburg and Berta of Limburg, Beatrice was born into the Meuse-Rhineland aristocracy. Her father was a supporter of Richard of Cornwall's claim to the imperial crown of Germany following Richard's coronation in Aachen. Her paternal uncle, Engelbert II of Falkenburg, archbishop-elector of Cologne, was neither loyal to Richard nor interested in him, but when he became imprisoned during the turmoil, when Richard's candidacy was opposed by Alfonso X of Castile who was elected by Saxony, Brandenburg and Trier, Richard decided to liberate him. In October 1268, the King along with the count of Falkenburg invaded the electorate of Cologne, only to be completely defeated; Beatrice's father was killed in the struggle and her uncle remained imprisoned.
During the conflict, Richard became infatuated with Beatrice, then 15 years old and renowned for her beauty. Concerned for her safety, Richard had her taken to her paternal half-uncle, Philip of Bolanden-Hohenfels, and soon began negotiating marriage with her. Beatrice became his third wife and queen of the Romans in Kaiserslautern on 16 June 1269. With her father dead and her powerful uncle hopelessly imprisoned, Beatrice was not a political asset; Richard married her simply because he was attracted to her and was unable to be separated from her for even one night. The chronicler Thomas Wykes nevertheless emphasises the political significance of the marriage: Beatrice was German and would bring the English king of Germany closer to his subjects and to his kingdom.
As no invitation to Rome for the couple's coronation as emperor and empress of the Holy Roman Empire was forthcoming, Richard announced that he wished to show Beatrice his vast lands in England and departed from Germany. They reached Dover on 3 August 1269 but neither ever returned to Germany.
Queen Beatrice was widowed in 1272. The couple had no children. Her husband was buried next to his second wife, Sanchia of Provence, but Beatrice may have organised the burial of his heart at the Franciscan church at Greyfriars, Oxford. She led an extremely low-profile life, almost disappearing from historical records. Her brother-in-law, King Henry III of England, sent her gifts in 1272, as did her nephew, King Edward I, in 1276. She was at odds with her stepson, Edmund, 2nd Earl of Cornwall, over part of his mother Sanchia's dower, but that was settled in February 1276. A portrait of Beatrice in stained glass, the oldest undamaged still existing donor portrait, was made by Norwich Greyfriars and is now part of the Burrell Collection in Glasgow. It was thought to originate from the Franciscan church in Oxford, which would have indicated that Beatrice was a significant benefactress to the order. This is the only indication that Beatrice donated to the Church. She died aged 23 on 17 October 1277. She was buried at Greyfriars, Oxford, as queen of Germany.