Clara de Büren was the second daughter of Jean de Büren and Nicola Mossü. She was lady of Signau and Worb and was one of the most famous women of her age. She would marry first Ulrich Rieder and then Louis (Loy) de Diesbach. Louis was lord of Diesbach, and a Bernese Senator. While Clara was important in her own right, she is known mostly today as the mother of Nicolas de Diesbach, Schultheis of Bern and key player in the Burgundian wars that would consume Switzerland in the 15th century.
Nicolas was the richest man in Bern in his day thanks to the family business, a multinational corporation that imported textiles. He was a Knight of the Holy Sepulchre, a great orator, very charismatic and given his political ambitions, rose quickly within the circles of Bernese power.
Nicolas is most well known for his role as an emissary for Louis XI of France in Bern. The following section on Nicolas comes from Capitaine de Vallière's masterwork on the Swiss in foreign service, Honneur et Fidélité. I have translated and interpreted the following section from the original.
Louis XI the Prudent, King of France
Through the use of a number of machiavellian measures Louis XI pushed the Swiss to war on his behalf against the bravest and most powerful Prince in Christendom, Charles the Bold. The King of France had one aim in the middle part of the 15th century: the destruction of the Duchy of Burgundy. To accomplish this goal he would need the military might of the Swiss.
Charles the Bold, Duke of Burgundy by Peter Paul Rubens
The confederates at that time were not at all interested in becoming embroiled in a quarrel between a King and his Vassal, they preferred to stay on good terms with both and remain neutral. To win over those who preferred peace, the King used several close allies, Jodoc de Silinen, of Luzern, Bishop of Grenoble, Guillaume de Diesbach, and especially his cousin Nicolas de Diesbach of Bern, a very talented diplomat. These men would take their mission very seriously, slowly turning public sentiment away from the alliance with Burgundy, all the while handing out French gold as they went. The public, duped by fabricated stories, now felt threatened by the ambitions of Charles the Bold, who was seen as a dangerous enemy with the darkest of intentions. The exodus of Swiss mercenaries in the service of Louis XI and France commenced.
1470 marked the first political success of Nicolas de Diesbach and showed his expanding influence. In light of the supposed eminent attack of Charles the Bold, eight Swiss cantons signed a defensive treaty with Louis XI. Four years later at the urging of Nicolas de Diesbach war would be declared against Charles and the Duchy of Burgundy. France and Louis XI would stay out of the fray, happy to have the Swiss fight Charles the Bold for them. The Burgundian Wars would last until 1477 when Charles the Bold died at the battle of Nancy.
Nicolas de Diesbach would die in 1475 of plague at Blamont near the beginning of hostilities with Burgundy. As a result of his death the Swiss lost their most able negotiator and when the war was over in 1477, Louis XI took clear advantage of the situation. History has judged Nicolas severely, most seeing him only as a puppet of Louis XI. If any positives can be drawn from the period is that the war that Nicolas de Diesbach lobbied for and helped bring about would substantiate the Swiss as a fighting force to be reckoned with for years to come.