William de Ros, 6th Baron de Ros of Helmsley, KG (c.1370 – 1 September 1414) was Lord Treasurer of England.
Margery (Margaret) le Despencer, de jure suo jure 3rd Baroness le Despenser (1387 creation), was the daughter and heiress of Philip le Despencer, 2nd Baron le Despencer.
 She was born about 1397 in Nettlestead, Suffolk, England, and married John de Ros, 7th Baron de Ros.
 He died without heirs, and she married secondly Roger Wentworth of Nettlestead, Esq. (d.1452), son of John Wentworth of North Elmsall.
Edmund de Ros or Roos, 10th Baron de Ros of Helmsley (c.1455 – 23 October 1508) was a follower of the House of Lancaster during the Wars of the Roses.
 He regained his family title after the accession of King Henry VII 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.
William de Ros or Roos, 1st Baron de Ros of Helmsley (c. 1255 – 6 or 8 August 1316), was one of the claimants of the crown of Scotland in 1292 during the reign of Edward I.
Thomas de Ros, 4th Baron Ros of Hamlake (13 Jan 1335 – 8 June 1384) was the son of William de Ros, 2nd Baron de Ros and Margery de Badlesmere.
Henry William FitzGerald-de Ros, 22nd Baron de Ros (12 June 1793 – 28/29 March 1839) was a British nobleman, the son of Lord Henry FitzGerald and his wife Charlotte FitzGerald-de Ros, 21st Baroness de Ros.
William de Ros, 2nd Baron de Ros of Hamlake (c. 1285 – 3 February 1343) was the son of William de Ros, 1st Baron de Ros of Hamlake and Maud de Vaux.
Baron de Ros of Helmsley (pronounced "Roose") is the premier baron in the Peerage of England, created in 1288/89 for William de Ros, with precedence to 24 December 1264.
 (The spelling of the title and of the surname of the original holders has been rendered differently in various texts.
 The word "Ros" is sometimes spelt "Roos", and the word "de" is sometimes dropped.)
William de Ros, 3rd Baron de Ros of Helmsley (19 May 1329 – c. 3 December 1352) was a military commander under Edward, the Black Prince.
 He was knighted by the Black Prince in 1346, having helped raise the siege of Aiguillon.
 In the same year, he was one of the lords who led the second division in the Battle of Crécy, and afterwards commanded the fourth division of the English army against the Scots, near Neville's Cross, when David Bruce, with many of the Scottish nobles, was taken prisoner.

Question: Who reformed royal administration, such as William de Ros, during his rein as King?
Answer: Edward I