Information:  - Peter of Luxembourg (1390  31 August 1433) was a son of John of Luxembourg, Lord of Beauvoir, and his wife Marguerite of Enghien. His inheritance included the counties of Brienne, Conversano and Saint-Pol.  - Jacquetta of Luxembourg, Countess Rivers (1415/1416  30 May 1472) was the eldest daughter of Peter I of Luxembourg, Count of Saint-Pol, Conversano and Brienne and his wife Margaret of Baux (Margherita del Balzo of Andria). She was a prominent, though often overlooked, figure in the Wars of the Roses. Through her short-lived first marriage to the Duke of Bedford, brother of King Henry V, she was firmly allied to the House of Lancaster. However, following the emphatic Lancastrian defeat at the Battle of Towton, she and her second husband Richard Woodville sided closely with the House of York. Three years after the battle and the accession of Edward IV of England, Jacquetta's eldest daughter Elizabeth Woodville married him and became Queen consort of England. Jacquetta bore Woodville 14 children and stood trial on charges of witchcraft, for which she was exonerated.  - Richard Woodville (or Wydeville), 1st Earl Rivers (1405  12 August 1469) was an English nobleman, best remembered as the father of Queen consort Elizabeth Woodville and the maternal grandfather of Edward V and the maternal great-grandfather of Henry VIII.  - The House of York was a cadet branch of the English royal House of Plantagenet. Three of its members became Kings of England in the late 15th century. The House of York was descended in the male line from Edmund of Langley, 1st Duke of York, the fourth surviving son of Edward III, but also represented Edward's senior line, being cognatic descendants of Lionel, Duke of Clarence, Edward III's second surviving son. It is based on these descents that they claimed the English crown. Compared with the House of Lancaster, it had a senior claim to the throne of England according to cognatic primogeniture but junior claim according to the agnatic primogeniture. The reign of this dynasty ended with the death of Richard III of England in 1485. It became extinct in the male line with the death of Edward Plantagenet, 17th Earl of Warwick in 1499.  - A queen consort is the wife of a reigning king (or an empress consort in the case of an emperor). In Brunei, the wife of the Sultan is known as a "Raja Isteri" with prefix "Pengiran Anak", equivalent with queen consort in English, as were the consorts of tsars when Bulgaria was still a monarchy. A queen consort usually shares her husband's social rank and status. She holds the feminine equivalent of the king's monarchical titles, but historically, she does not share the king's political and military powers. A queen regnant is a queen in her own right with all the powers of a monarch, who (usually) has become queen by inheriting the throne upon the death of the previous monarch.  - Cecily of York , Viscountess Welles ( 20 March 1469 -- 24 August 1507 ) was an English Princess and the third , but eventual second surviving , daughter of Edward IV , King of England and his queen consort Elizabeth Woodville , daughter of Richard Woodville , 1st Earl Rivers and Jacquetta of Luxembourg .  - Sir John Grey, of Groby, Leicestershire (c. 1432  17 February 1461) was a Lancastrian knight, the first husband of Elizabeth Woodville who later married King Edward IV of England, and great-great-grandfather of Lady Jane Grey.  - Margaret of Baux (; 1394  15 November 1469) was a Countess of Saint-Pol, of Brienne, and of Conversano. She was a member of the noble House of Baux of the Kingdom of Naples, which had its origins in Provence dating back to the 11th century. Her husband was Peter of Luxembourg, Count of Saint-Pol, of Brienne, and of Conversano (1390  31 August 1433). Margaret's descendants include English Queen Consort Elizabeth Woodville, King Henry IV of France, Mary, Queen of Scots, and all English monarchs after 1509.  - Sultan (') is a noble title with several historical meanings. Originally, it was an Arabic abstract noun meaning "strength", "authority", "rulership", derived from the verbal noun ', meaning "authority" or "power". Later, it came to be used as the title of certain rulers who claimed almost full sovereignty in practical terms (i.e., the lack of dependence on any higher ruler), albeit without claiming the overall caliphate, or to refer to a powerful governor of a province within the caliphate.  - The House of Lancaster was the name of two cadet branches of the royal House of Plantagenet. The first house was created when Henry III of England created the Earldom of Lancasterfrom which the house was namedfor his second son Edmund Crouchback in 1267. Edmund had already been created Earl of Leicester in 1265 and was granted the lands and privileges of Simon de Montfort, 6th Earl of Leicester, after de Montfort's death and attainder at the end of the Second Barons' War. When Edmund's son Thomas, 2nd Earl of Lancaster, inherited his father-in-law's estates and title of Earl of Lincoln he became at a stroke the most powerful nobleman in England, with lands throughout the kingdom and the ability to raise vast private armies to wield power at national and local levels. This brought himand Henry, his younger brotherinto conflict with their cousin Edward II of England, leading to Thomas's execution. Henry inherited Thomas's titles and he and his son, who was also called Henry, gave loyal service to Edward's sonEdward III of England.  - Elizabeth Woodville (also spelled Wydville, Wydeville, or Widvile; c. 1437  8 June 1492) was Queen consort of England as the spouse of King Edward IV from 1464 until his death in 1483. At the time of her birth, her family was mid-ranked in the English aristocracy. Her first marriage was to a minor supporter of the House of Lancaster, Sir John Grey of Groby; he died at the Second Battle of St Albans, leaving Elizabeth a widowed mother of two sons. Her second marriage, to Edward IV, was a cause célèbre of the day, thanks to Elizabeth's great beauty and lack of great estates. Edward was only the second king of England since the Norman Conquest to have married one of his subjects, and Elizabeth was the first such consort to be crowned queen. Her marriage greatly enriched her siblings and children, but their advancement incurred the hostility of Richard Neville, Earl of Warwick, 'The Kingmaker', and his various alliances with the most senior figures in the increasingly divided royal family.    What is the relationship between 'cecily of york' and 'edward iv of england'?
Answer:
father