Question: The person who was king of England when William de Botreaux, 1st Baron Botreaux died was born on what date?

Context paragraphs:
Hall, Lanteglos-by-Fowey: Hall in the parish of Lanteglos-by-Fowey in Cornwall, England, is an historic estate, most prominent as the seat of a branch of the Mohun family, feudal barons of Dunster, of Dunster Castle in Somerset, of whom the first member, the warrior William de Moyon (died post 1090), had come over with William the Conqueror during the Norman Conquest of 1066.  The family of Mohun of Hall was also seated at Bodinnick ("alias" Bodinnoc, etc.) also in the parish of Lanteglos-by-Fowey and later at Boconnoc, both in Cornwall, and was one of the four co-heirs of Edward Courtenay, 1st Earl of Devon (1527–1556), feudal baron of Okehampton, etc., of Tiverton Castle, Okehampton Castle, etc., the last of the mediaeval Courtenay Earls of Devon.  In recognition of this in 1628 the senior representative of the Mohun family of Hall was created Baron Mohun of Okehampton, namely John Mohun, 1st Baron Mohun of Okehampton (1595-1641) eldest son and heir of Sir Reginald Mohun, 1st Baronet (1564–1639) of Boconnoc.  The family of Mohun of Hall died out in the male line in 1712, following the death by duel of Charles Mohun, 4th Baron Mohun of Okehampton (1677-1712), who died without progeny.  However, the family had long out-lived the senior Dunster line which died out in the male line in 1375, following the death of John de Mohun, 2nd Baron Mohun, KG, (c.1320-1375).  Two monumental brasses survive in Lanteglos church to members of the Mohun family of Hall, namely Thomas Mohun (died c.1440) and John Mohun (d.1508).

William de Botreaux, 1st Baron Botreaux: William de Botreaux (1337–1391) (pronounced "But'ry") (alt.  “Bottreaux, Boterel etc.) was a prominent English West-Country baron during the reigns of King Edward III (1327-1377) and King Richard II (1377-1399).

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.

Baron Ferrers of Groby: Baron Ferrers of Groby (or Baron Ferrers de Groby) was a title in the Peerage of England.  It was created by writ on 29 December 1299 when William Ferrers, 1st Baron Ferrers of Groby was summoned to parliament.  He was the son of Sir William de Ferrers, Knt., of Groby, Leicestershire, (d.1287) by his first wife Anne Durward, 2nd daughter of Alan Durward and his wife Margery of Scotland, and grandson of William de Ferrers, 5th Earl of Derby.  The first Baron was married to Ellen de Menteith, daughter of Alexander, Earl of Menteith.  In 1475 the eighth baron was created the Marquess of Dorset, and the barony in effect merged with the marquessate.  It was forfeited along with the marquessate when the third marquess was attainted in 1554.

Baron Howick of Glendale: Baron Howick of Glendale, of Howick in the County of Northumberland, is a title in the Peerage of the United Kingdom.  It was created in 1960 for Sir Evelyn Baring, the former Governor of Kenya.  A member of the famous Baring family, he was the third and youngest son of Evelyn Baring, 1st Earl of Cromer, and the great-grandson of Sir Francis Baring, 1st Baronet, the founder of Barings Bank.  Baring's uncle was Edward Baring, 1st Baron Revelstoke, the father of Maurice Baring, while other members of the family include Francis Baring, 1st Baron Northbrook, and Alexander Baring, 1st Baron Ashburton.  s of 2014 the title is held by the first Baron's son, the second Baron, who succeeded in 1973.  As a descendant of the first Earl of Cromer and Sir Francis Baring, 1st Baronet, he is in remainder to both the earldom of Cromer and its subsidiary titles and the Baring baronetcy of Larkbeer, titles held by his kinsmen the Earl of Cromer and the Baron Northbrook respectively.

William de Botreaux, 2nd Baron Botreaux: William de Botreaux (1367–1395) (pronounced "But'ry") was a baron prominent in South-West England.

Baron Revelstoke: Baron Revelstoke, of Membland in the County of Devon, is a title in the Peerage of the United Kingdom.  It was created in 1885 for the businessman Edward Baring, head of the family firm of Barings Bank and a member of the Baring family.  Baring was the son of Henry Baring, third son of Sir Francis Baring, 1st Baronet, and the nephew of Alexander Baring, 1st Baron Ashburton, the second cousin of Francis Baring, 1st Baron Northbrook, the elder brother of Evelyn Baring, 1st Earl of Cromer and the uncle of Evelyn Baring, 1st Baron Howick of Glendale.  He was succeeded by his second but eldest surviving son John, the second Baron.  John was a partner in Baring Brothers and Co. Ltd, a Director of the Bank of England, and also served as Lord Lieutenant of Middlesex.  On his death the title passed to his younger brother Cecil, the third Baron.  He acquired Lambay Island, north of Dublin, in 1904.  s of 2013 the title is held by his great-grandson, the seventh Baron, who succeeded his father in 2012.  As a descendant of Sir Francis Baring, 1st Baronet, he is also in remainder to the Baring Baronetcy of Larkbeer, a title held by his kinsman the Baron Northbrook.

William de Botreaux, 3rd Baron Botreaux: William de Botreaux, 3rd Baron Botreaux (1389–1462) was a prominent baron in Somerset and the south-west of England.  He inherited from his father the barony by writ of Botreaux as well as substantial family landholdings which included a moiety of the feudal barony of North Cadbury, Somerset, in the parish church of which capital manor he was buried, as he requested in his will.

Baron Botreaux: Baron Botreaux (pronounced "But'ry") is a title in the Peerage of England.  It was created by writ of summons in 1368 by Edward III for William de Botreaux, 1st Baron Botreaux.

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.

Supporting paragraphs: William de Botreaux, 1st Baron Botreaux Richard II of England
Answer: 6 January 1367