Jean de Forcade de Biaix, aka Jean de Forcade, Marquis de Biaix, aka Jean-Quirin de Forcade de Biaix, aka Jean Quérin von Forcade, Herr von Biaix, aka Johann Querin de Forcade, Herr zu Biaix, aka Johann Quirin von Forkade de Biaix ( – ) was a Huguenot, a descendant of the noble family of Forcade and Lieutenant General in the service of the Kingdom of Prussia. He was the Regimentschef of the 23rd Prussian Infantry Regiment, Commandant of the Royal Residence in Berlin, Gouverneur militaire of Berlin, a Knight of the Order of the Black Eagle a member of King Frederick I of Prussia's "Tobacco Collegium". and president of the Grand Directoire 1718–1729, the deliberative and decision-making body responsible for all Huguenot affairs in the kingdom. Although there are references to Jean de Forcade de Biaix as the "Marquis de Biaix" in some Prussian sources published between 1788 and 1837, there is no evidence that he was ever a Marquis. The noble manor of Biaix in the city of Pau was never a marquisate, at any time in its history. He was also never the Seigneur de Biaix, as stated in some historical Prussian sources. The title Seigneur was not hereditary. In the case of his family, his father, who purchased Biaix manor in 1659, was the Seigneur de Biaix. Following the father's death in 1684, the property and the right to enter the Order of Nobility of the Estates of Béarn were passed to the eldest son, Jean's elder brother, Isaac de Forcade de Biaix (Seigneur de Biaix 1684–1737). Little is known about his early life. His parents were Protestant. Protestant church records do not exist for the period between 1617 and 1667 for the Temple in Pau. Historical records published in the 19th century related to the research of noble families in France claim that only two branches of this family descended from the parents, and that the only surviving branch was the Prussian one. Protestant baptismal records for the Temple in Pau for the period 1668–1681 and 1673–1684, however, point to a large family with no fewer than 11 children, of which six sons to carry the name forward.