Question: What is the date of death of Joan, Countess Of Blois's mother?

Knowledge 1: Joan, Countess of Blois
Joan of Châtillon ("Jeanne de Blois"; 1253? – 19 or 29 January 1291) was Countess of Blois from 1280 to 1291, and Lady of Avesnes.She was the daughter of John I, Count of Blois and Alix of Brittany, Dame de Pontarcy.Joan received the County of Chartres from her father during his life; she later sold these lands to Philip IV of France in 1286.She ceded the lordship of Avesnes to her cousin Hugh before her death.When she died in 1291 the other titles were left to him also.In 1263, Joanne married Peter of Alençon, a son of King Louis IX of France and Margaret of Provence.They had two sons who both died in infancy:Joan died in 1291, with no living issue.She left the title of Count of Blois and her remaining titles to her cousin Hugh. [SEP] Knowledge 2: Alix of Brittany, Dame de Pontarcy
Alix of Brittany, Dame de Pontarcy, Countess of Blois (6 June 1243 – 2 August 1288), was a Breton noblewoman and a member of the House of Dreux as the eldest daughter of John I, Duke of Brittany.She married John I, Count of Blois.Alix was known for founding religious houses including the Monastery of La Guiche, where she was later buried.Alix, named after her paternal grandmother, Alix of Thouars, was born on 6 June 1243 at the Château de Suscinio in Sarzeau, Morbihan, Brittany.She was the eldest daughter of John I, Duke of Brittany and Blanche of Navarre, daughter of Theobald I of Navarre and Agnes of Beaujeu.Alix held the title "Dame de Pontarcy" in her own right.Sometime after a contract was signed on 11 December 1254, she married John I, Count of Blois of the House of Châtillon.Thereafter she was styled Countess of Blois.She brought as her dowry her titles of Pontarcy and de Brie-Comte-Robert, which had been named after her ancestor Robert I of Dreux.The marriage produced one child, a daughter Jeanne, who was heiress to her father's title and estates.In 1270, her husband was appointed Lieutenant General of France.Through Alix's marriage to John, the Château de Brie-Comte-Robert passed to the Châtillon family.Alix and John founded several religious houses including the Monastery of La Guiche near Blois in 1277.She became a widow on 28 June 1279.In 1287, the year before her own death, Alix travelled to Palestine.From there she journeyed on to Syria, where she commissioned the erection of two barbican towers at Ptolemais.
Knowledge 1: Joan, Countess of Blois
Joan of Châtillon ("Jeanne de Blois"; 1253? – 19 or 29 January 1291) was Countess of Blois from 1280 to 1291, and Lady of Avesnes.She was the daughter of John I, Count of Blois and Alix of Brittany, Dame de Pontarcy.Joan received the County of Chartres from her father during his life; she later sold these lands to Philip IV of France in 1286.She ceded the lordship of Avesnes to her cousin Hugh before her death.When she died in 1291 the other titles were left to him also.In 1263, Joanne married Peter of Alençon, a son of King Louis IX of France and Margaret of Provence.They had two sons who both died in infancy:Joan died in 1291, with no living issue.She left the title of Count of Blois and her remaining titles to her cousin Hugh. [SEP] Knowledge 2: Margaret, Countess of Blois
Margaret of Blois( French:" Marguerite"; died 1230) was" suo jure" Countess of Blois from 1218 to 1230, in what is now France.
Knowledge 1: Joan, Countess of Blois
Joan of Châtillon ("Jeanne de Blois"; 1253? – 19 or 29 January 1291) was Countess of Blois from 1280 to 1291, and Lady of Avesnes.She was the daughter of John I, Count of Blois and Alix of Brittany, Dame de Pontarcy.Joan received the County of Chartres from her father during his life; she later sold these lands to Philip IV of France in 1286.She ceded the lordship of Avesnes to her cousin Hugh before her death.When she died in 1291 the other titles were left to him also.In 1263, Joanne married Peter of Alençon, a son of King Louis IX of France and Margaret of Provence.They had two sons who both died in infancy:Joan died in 1291, with no living issue.She left the title of Count of Blois and her remaining titles to her cousin Hugh. [SEP] Knowledge 2: Theobald V, Count of Blois
Theobald V of Blois( 1130 – 20 January 1191), also known as Theobald the Good, was Count of Blois from 1151 to 1191.

Answer: 2 August 1288