Oton III de Grandson

Oton III de Grandson, name also spelled Otto, Othon, etc. (died 7 August 1397), was a nobleman, soldier, and poet in fourteenth century France. Although his military service was primarily to the King of England, his reputation for chivalry and poetry was renowned throughout Europe.
Life.
Oton de Grandson was born in Savoy between 1340 and 1350 to William of Grandson and his wife Jeanne of Vienna. His family was of the highest nobility. On September 25, 1365, he married Jeanne d'Allamande, daughter of Humbert d'Allamand, lord of Aubonne and Coppet.
He was captured in combat in 1372 by the Spanish, allies of France, and spent two years in prison. In 1374 he was ransomed by the King of England Edward III and returned to military service. When his father died in 1386, he returned to Savoy and inherited the lordship of Sainte-Croix, Grandcour, Cudrefin, Aubonne and Coppet. He became the primary advisor of Amédée VII, called the Red Count. He was imprisoned again for some time in 1389 for unknown reasons. 
Duel.
When the Red Count died following an accident on horseback, his mother Bonne of Bourbon, was accused of murdering him. Oton was also implicated in the ensuing controversy that pitted the various regional lords against each other. Oton fled to England; he was condemned and his lands confiscated in 1393. In 1395, however, Oton was declared innocent by the French king, Charles VI and he returned to Savoy. Accusations against him were renewed, however, and he was forced to engage in a judicial combat by the young count Amédée VIII. He was killed by his accuser, Gérard d'Estavayer, a much younger man, on August 7, 1397. A near contemporary poet, Olivier de la Marche, recorded the details of the duel in his chronicle "Livre de l'advis du gaige de bataille".
The château of Oton de Grandson, dating from the 11th century, is in Switzerland.
Reputation.
Oton de Grandson had a reputation as a fine and courteous knight. The poet and chronicler Jean Froissart hails him as the paragon of knightly valor in his "Chroniques". However, it is his poetic prowess that endures. He is celebrated by poets such as Eustache Deschamps, Christine de Pizan, Alain Chartier, Martin Le Franc, Georges Chastellain, Oliver de La Marche and Geoffrey Chaucer, all of whom imitated his courtly poetry. He was friends with Deschamps and Chaucer.
The woman loved faithfully by Oton de Grandson, sometimes referred to as Isabelle (in acrostic in the Souhait de saint Valentin, the Complainte de Grandson, and the Songe de saint Valentin) also called "la non-per France," of too high estate for him to hope for, might have been Isabeau de Bavière, queen of Charles VI. This steadfast love, faithful even to death, voiced over and over through his poetry, earned him the reputation of the most courtly lover in France.
Poetry.
Oton de Grandson composed around 80 poems during his life, for a total of more than 6,000 verses. Among them are
Arthur Piaget, Oton de Granson et ses poésies. "Romania", 19 (1890) p. 237-259, 403-448.
"Kosta-Théfaine, Jean-François, Othon de Grandson, chevalier et poète, Éditions Paradigme, Medievalia, 2007"
Manuscripts and editions.
At least 18 manuscripts conserve his poetic works, although there is no extant manuscript written in his hand.
Several of his ballads are included in the Jardin de Plaisance et Fleur de Rhétorique (1501).