Title: Sancho, Count of Provence
Content:  Sancho (died 1223), also spelled Sanç or Sanche, was a Catalano-Aragonese nobleman and statesman,  the youngest son of Queen Petronilla of Aragon and Count Raymond Berengar IV of Barcelona. He was at different times the count of Cerdanya (c.1175–1188), Provence (1181–1185), Gévaudan, Rodez and Carlat (1183–1185), and Roussillon (1208–1212). He served as the regent of Provence from 1209 until 1218 during the minority of Count Raymond Berengar IV, and as regent of Aragon from 1214 until 1218, during the minority of King James I.
Title: Sancho, Count of Provence
Content: Francs reis, Proensa·us apella, ; qu'En Sancho la·us desclavella, ; e gasta·us la cer'e·l mel ; e sai tramet vos lo fel. (Noble king, Provence is calling out to you, it is being despoiled by Lord Sancho, he is taking the wax and honey and sending you nothing but gall.) Proenza pert, don es eissitz, ; que so frair Sanso prezan mais... (He [Alfonso] is losing Provence, which he left, where his brother Sancho is better loved...) Sancho's first responsibility after inheriting the county of Provence in 1181 was to defend the county from the claims of Count Raymond V of Toulouse. For the 
Title: Sancho, Count of Provence
Content:  Sometime before 1184, Sancho married Ermessenda, daughter of Geoffrey I of Rocabertí and Ermessenda de Vilademuls. In 1185, he married Sancha Núñez de Lara, daughter of Count Nuño Pérez de Lara and Teresa Fernández de Traba, and thus a step-daughter of King Ferdinand II of León. By her he had his only known son, Nuño Sánchez.
Title: Sancho, Count of Provence
Content:  Sancho was a minor at the time of his father's death (1162) and he did not inherit lands or titles, but only the right of reversion should his elder brothers die without heirs. Thus, according to his father's will, he should have inherited Provence and Cerdanya only after his elder brother Raymond Berengar III, count of Provence, was assassinated in 1181. In fact, while he inherited Provence at that time, he appears to have received Cerdanya shortly before that. Sancho came of age between 1175, when he first began witnessing the royal charters of his eldest brother, King Alfonso II of Aragon, and 1180. In these years, he witnessed charters only in Catalonia and Provence. Before 1180, he occasionally signed documents with the title "Count of Cerdanya" (comes Ceritanie), but usually he was described as just "the king's brother". Alfonso does not seem to have entirely trusted his administration of Cerdanya, for he intervened in the county in 1177 and again in 1188. Sancho is not recorded as count of Cerdanya after that.
Title: Sancho, Count of Provence
Content:  in Aix by March 1185, when the dating clause of a charter reads "when we recovered Provence from the hands of Sancho, our brother". Evidence of Alfonso's ill-will towards can be found in the Gesta comitum Barcinonensium, which records that Alfonso "never loved [his brother Sancho] and did not wish to give him anything in his kingdom." The hostility between Sancho and Alfonso caught the notice of the troubadour Peire Vidal, who addresses the king in a tornada:    By contrast, the troubadour Bertran de Born presents Sancho as popular in Provence:  After his removal from office, Sancho continued to style himself Count of Provence.
Title: Sancho, Count of Provence
Content:  Alfonso's successor in Provence, Count Alfonso II, died. He left behind a minor, Raymond Berengar IV, as his heir. King Peter appointed Sancho governor of Provence on behalf of Raymond Berengar. One of his first tasks was to subdue the rebellious city of Arles. Sancho also promptly brought his own son, Nuño, into the government of Provence. Together they pursued a policy that favoured communal liberties and commercial activity while opposing encroaching French and Papal influence. As a base of support in Provence, Peter granted Sancho and Nuño the ports of Agazi, Boch and Monaco. In 1212, Sancho fought at the Battle of Las Navas de Tolosa on the side of 
Title: Sancho, Count of Provence
Content:  four years, Sancho and his brother Alfonso prosecuted a war against Toulouse. On 9 December 1182, Alfonso visited his brother in Aix and exempted the Knights Hospitaller from commercial duties and tolls in Provence. In March 1183, Alfonso enfeoffed Sancho with the counties of Gévaudan, Rodez and Carlat. Sancho's expense account for his stay at Perpignan in November 1184, where he met his brother, has survived and provides a detailed look at how his court functioned. Early in his administration of Provence, conflict arose every spring between him and the neighbouring prince, Count William IV of Forcalquier. Finally, in 1184, Sancho signed a treaty 
Title: Sancho, Count of Provence
Content:  alliance with the count of Forcalquier, the count of Toulouse and the Republic of Genoa agreeing to oppose the king of Aragon's efforts to dominate Genoa and to take the city of Marseille from him. Sancho then intervened on the side of Genoa in that commune's war against Pisa. These actions of disloyalty caused a rift between the brothers, and Alfonso dispossessed Sancho of Provence, Gévaudan, Rodez and Carlat. In his place he appointed Roger-Bernard I, count of Foix, as his bailiff or procurator in Provence. According to some historians, the king was merely looking for an excuse to seize control of Provence. Alfonso 
Title: Sancho, Count of Provence
Content:  orbit, Sancho arranged for his son Nuño to marry Gaston's widow, the hereditary countess Petronilla, in 1215. The plan failed when the clergy annulled the marriage in 1216. Petronilla ended up marrying Guy de Montfort, brother of Simon. In November 1215, Sancho sent two envoys, Pedro Ahones and Guillem IV de Cervera, to attend the Fourth Council of the Lateran in Rome as representatives of Aragon. At the council, they undermined Sancho's anti-crusade policy, alongside Bishop Hispan of Segorbe. In the end, the council upheld the legality of the crusade. In a letter addressed to Pope Innocent III, Sancho had also 
Title: Sancha of Aragon, Countess of Toulouse
Content:  Sancha of Aragon (1186&ndash;1241) was the daughter of King Alfonso II of Aragon and his wife, Sancha of Castile. Through her marriage to Raymond VII, Count of Toulouse in 1211, she acquired the titles Countess of Toulouse and Marquise of Provence from then until their divorce in 1241. Sancha's paternal grandparents were Ramon Berenguer IV, Count of Barcelona and Petronilla of Aragon; her maternal grandparents were Alfonso VII of León and Castile and Richeza of Poland, Queen of Castile. She was the sister of Peter II of Aragon and Alfonso II, Count of Provence. She had one child, Joan, Countess of Toulouse, who held the same titles as her mother from 1249 to 1271.

Question: Who is the mother of Sancho, Count of Provence?
Answer: Petronilla of Aragon.