I came across this old post about Aelfwine, but since it's still showing up in searches, I thought I'd reply the answer to your question. The Alboynus you read about in association with Conques, France is a Latinized form of the Anglo-Saxon name Aelfwine. He was the son of Harald I of England, better known as Harald Harefoot, son of King Cnut and Aelfgifu of Northampton. I am a writer and historian working on a project about Aelfgifu of Northampton, and the other wife of King Cnut, Emma of Normandy.
Yes, Cnut had two living wives at the same time, not unusual for Scandianvian kings but only acceptable to Christian England at the time because his first marriage to Aelfgifu was a Viking handfasting, and not blessed by the Church, while his second marriage to Emma (the widow of the former King Aethelred II) was consecrated and kept her powerful Norman family from invading England in 1017. Cnut converted, but he kept both wives and recognized his two sons by Aelfgifu -- Svein, the elder, and Harald -- as legitimate heirs. Svein was named King of Norway in 1030 by his father, but died the winter of 1035-6, shortly after Cnut. Cnut and Emma had a son, Harthacnut, who by a signed document was supposed to inherit the English throne before his older half-brothers. But Harthacnut, already King of Denmark, was extremely slow in returning to England to claim the throne, and in his absence, Harald was first named regent, then crowned King in 1037. A will of Bishop Aelfric of Elmham (d. 1038) names his "lord" King Harald and his "lady," who receive token bequests. The "lady" (hlaefdige, a term used for Anglo-Saxon queens) is clearly Harald's wife and some sort of relation to Bishop Aelfric.
The Abbey of Conques, France has two charters relating to Aelfwine/Alboynus/Albodenus, dated 1060 and 1062, where he is described as "of the stock of kings, who came from the uttermost parts of Angle-land" and "Alboynus Anglorum" born in London, his father Harald King of Angle-land, his mother named "Alvena," a "nobleman and loyal christian."
The placing of Aelfwine in France, along the pilgrim route to Compostela in Spain, is not so far-fetched when the events of 1040 in England are considered. King Harald, only 24, dies suddenly at Oxford, possibly of poison. Harthacnut, already in Flanders with an invasion fleet, quickly arrives and is proclaimed King. He orders Harald's body dug up from Winchester Cathedral, beheaded, and thrown into a bog. At this point in history, Aelfgifu, Harald's mother, disappears entirely from the records. If Harald had a young son, Aelfwine, by his wife, also named Aelfgifu (a popular name at the time), then the child's life would have been in mortal danger. King Cnut had made two pilgrimages to Rome along the Via Francigena, leading from Calais across the English Channel through northern France, down to the Swiss border, completely bypassing Normandy. Only this pilgrim route could offer Aelfgifu and her grandson Aelfwine any protection from King Harthacnut's Norman relatives. A branch off this route had recently (prior to 1060) routed pilgrims to Compostela through Conques, and hence, the abbey church needed to be enlarged to accommodate them.
By the time Aelfwine/Alboynus, son of King Harald I, arrives, it seems his grandmother had either died or stayed behind at another location. Harald I is often forgotten in English history; he reigned for only 4 years, and apparently without much incident, based on the Anglo-Saxon Chronicle. The momentous events surrounding his distant cousin, Harald II in 1066, seem to have eclipsed his entire family line. But given the dangerous situation in England, with the rise to power of the half-Normans -- Harthacnut and Edward -- maybe Aelfwine was wise to never claim the throne.