Question: How many years is the reign of this King of England, who was remebered by his relationship with Catherine Grandison, Countess of Salisbury?

full_context: Document 1: Katherine Swynford: Katherine Swynford, Duchess of Lancaster (November 25, 1350 – May 10, 1403) (also spelled Katharine or Catherine), was the third wife of John of Gaunt, Duke of Lancaster, a son of King Edward III. She had been the Duke's lover for many years before their marriage. The couple's children, born before the marriage, were later legitimated during the reign of the Duke's nephew, Richard II. When the Duke's son from his first marriage overthrew Richard, becoming Henry IV, he introduced a provision that neither they nor their descendants could ever claim the throne of England.
Document 2: Edward I of England: Edward I (17/18 June 1239 – 7 July 1307), also known as Edward Longshanks and the Hammer of the Scots (Latin: "Malleus Scotorum" ), was King of England from 1272 to 1307. He spent much of his reign reforming royal administration and common law. Through an extensive legal inquiry, Edward investigated the tenure of various feudal liberties, while the law was reformed through a series of statutes regulating criminal and property law. Increasingly, however, Edward's attention was drawn towards military affairs.
Document 3: Edward III of England: Edward III (13 November 1312 – 21 June 1377) was King of England from 25 January 1327 until his death; he is noted for his military success and for restoring royal authority after the disastrous and unorthodox reign of his father, Edward II. Edward III transformed the Kingdom of England into one of the most formidable military powers in Europe. His long reign of 50 years was the second longest in medieval England and saw vital developments in legislation and government—in particular the evolution of the English parliament—as well as the ravages of the Black Death.
Document 4: Catherine Woodville, Duchess of Buckingham: Catherine Woodville (or Wydeville; c. 1458 – 18 May 1497) was an English medieval noblewoman. She was the sister-in-law of King Edward IV of England and gave birth to several illustrious children. Catherine was the daughter of Richard Woodville, 1st Earl Rivers, and Jacquetta of Luxembourg. When her sister Elizabeth married King Edward IV, the King elevated and promoted many members of the Woodville family. Elizabeth Woodville's household records for 1466/67 indicate that Catherine was being raised in the queen's household.
Document 5: Richard II of England: Richard II (6 January 1367 – c. 14 February 1400), also known as Richard of Bordeaux, was King of England from 1377 until he was deposed on 30 September 1399. Richard, a son of Edward, the Black Prince, was born in Bordeaux during the reign of his grandfather, Edward III. His father was Prince of Aquitaine. Richard was the younger brother of Edward of Angoulême, upon whose death Richard, at three years of age, became second in line to the throne after his father. Upon the death of Richard's father prior to the death of Edward III, Richard, by primogeniture, became the heir apparent to the throne. With Edward III's death the following year, Richard succeeded to the throne at the age of ten.
Document 6: Edward III of England: Edward III (13 November 1312 – 21 June 1377) was King of England from 25 January 1327 until his death; he is noted for his military success and for restoring royal authority after the disastrous and unorthodox reign of his father, Edward II. Edward III transformed the Kingdom of England into one of the most formidable military powers in Europe. His long reign of 50 years was the second longest in medieval England and saw vital developments in legislation and government—in particular the evolution of the English parliament—as well as the ravages of the Black Death.
Document 7: John de Montagu, 1st Baron Montagu: John de Montacute (  1330 –  1390 ) was a 14th-century English nobleman and loyal servant of King Edward III. He was the son of William Montagu, 1st Earl of Salisbury by his wife Catherine Grandison, and younger brother of William de Montacute, 2nd Earl of Salisbury (1328–1397). He also had several younger sisters.
Document 8: Issue of Edward III of England: King Edward III of England is the ancestor of many European monarchs (as well as the issue of many English Dukes, Earls and Viscounts) through his sons Lionel of Antwerp, 1st Duke of Clarence; John of Gaunt, 1st Duke of Lancaster; Edmund of Langley, 1st Duke of York and Thomas of Woodstock, 1st Duke of Gloucester. All of Edward's legitimate children were by his wife Philippa of Hainault.
Document 9: Edward IV of England: Edward IV (28 April 1442 – 9 April 1483) was the King of England from 4 March 1461 to 3 October 1470, and again from 11 April 1471 until his death in 1483. He was the first Yorkist King of England. The first half of his rule was marred by the violence associated with the Wars of the Roses, but he overcame the Lancastrian challenge to the throne at Tewkesbury in 1471 to reign in peace until his sudden death. Before becoming king, he was 4th Duke of York, 7th Earl of March, 5th Earl of Cambridge and 9th Earl of Ulster. He was also the 65th Knight of the Order of the Golden Fleece.
Document 10: Eleanor de Clare: Eleanor de Clare, suo jure 6th Lady of Glamorgan (3 October 1292-30 June 1337) was a powerful English noblewoman who married Hugh Despenser the Younger and was a granddaughter of Edward I of England. With her sisters, Elizabeth de Clare and Margaret de Clare, she inherited her father's estates after the death of her brother, Gilbert de Clare, 8th Earl of Gloucester, 7th Earl of Hereford at the Battle of Bannockburn in 1314. She was born in 1292 at Caerphilly Castle in Glamorgan, Wales and was the eldest daughter of Gilbert de Clare, 6th Earl of Hertford, 7th Earl of Gloucester, 5th Lord of Glamorgan and Princess Joan of Acre.
Document 11: Edward V of England: Edward V (2 November 1470 – ) was King of England from his father Edward IV's death on 9 April 1483 until 26 June of the same year. He was never crowned, and his 78-day reign was dominated by the influence of his uncle and Lord Protector, Richard, Duke of Gloucester, who succeeded him as Richard III on 26 June 1483; this was confirmed by the Act entitled Titulus Regius, which denounced any further claims through his father's heirs.
Document 12: Catherine Grandison, Countess of Salisbury: Catherine Grandison, Countess of Salisbury (c. 1304 – 23 November 1349) was an English noblewoman, remembered for her relationship with King Edward III of England and possibly the woman in whose honour the Order of the Garter was originated. She was the daughter of William de Grandison, 1st Baron Grandison, and Sibylla de Tregoz. Her mother was one of two daughters of John de Tregoz, Baron Tregoz (whose arms were blazoned "Gules two bars gemels in chief a lion passant guardant or"), maternal granddaughter of Fulk IV, Baron FitzWarin). Catherine married William Montacute, 1st Earl of Salisbury in about 1320.
Document 13: Alice FitzAlan, Countess of Kent: Alice Holland, Countess of Kent (c. 1350 – 17 March 1416), LG, formerly Lady Alice FitzAlan, was an English noblewoman, a daughter of the 10th Earl of Arundel, and the wife of the 2nd Earl of Kent, the half-brother of King Richard II. As the maternal grandmother of Anne Mortimer, she was an ancestor of King Edward IV and King Richard III, as well as King Henry VII and the Tudor dynasty through her daughter Margaret Holland. She was also the maternal grandmother of Joan Beaufort, Queen of Scotland.
Document 14: Eleanor Holland, Countess of Salisbury: Eleanor Holland, Countess of Salisbury (1386- after 1413), was an English noblewoman, the daughter of Thomas Holland, 2nd Earl of Kent, a half-brother of King Richard II of England. She was the first wife of Thomas Montacute, 4th Earl of Salisbury. One of her brothers was Edmund Holland, 4th Earl of Kent, to whom she was co-heiress. She is not to be confused with her eldest sister Alianore Holland, Countess of March who bore the same name.
Document 15: Edward II of England: Edward II (25 April 1284 – 21 September 1327), also called Edward of Caernarfon, was King of England from 1307 until he was deposed in January 1327. The fourth son of Edward I, Edward became the heir to the throne following the death of his older brother Alphonso. Beginning in 1300, Edward accompanied his father on campaigns to pacify Scotland, and in 1306 he was knighted in a grand ceremony at Westminster Abbey. Edward succeeded to the throne in 1307, following his father's death. In 1308, he married Isabella of France, the daughter of the powerful King Philip IV, as part of a long-running effort to resolve the tensions between the English and French crowns.
ground_truth: 50