The Le Strange Website states that Hamon had no children. It is not clear if he married.
Dates of death given by two sources do not mesh with birth dates of the children. The Le Strange Website reports that Hamon died about 1317, and an anonymous One World Tree reports a date of 1316. But the date of birth of the sons is given in sources as 1325. The Le Strange Website indicates that brothers Edmund and Hamon are twins, but gives no date. The anonymous One World Tree gives the date of 1325. This date seems reasonable, and lacking a date form more credible sources I am using that date for the birth of the twins. I am reporting no date of death for their father Sir Hamon This is one of the common difficulties in trying to sort out these families.
The Tudorplace information on the Le Strange family has Hawyse (Hawise) as the wife of Griffith ap Wennonwen, and mother of Owen ap Griffith de la Pole, Prince of Powys. Others have her as the wife of Owen. Because of the careful detail and explanations I find in the Tudorplace Le Strange genealogy, I am following that on this question. The dates given for the marriage of Griffith ap Wennonwen to Hawyse Le Strange would mean she was married at age 8. This seems strange, but child marriage was a common pattern among the Norman and other nobility in the Middle Ages. Few details are available in sources, so I am following this information from the Tudorplace genealogy, until I find more firm information that provides a better date or additional information to clarify this situation.
Some genealogies show this Henry Le Strange (born 1432) as a son of John Le Strange (born 1387) and a brother to Roger Le Strange (born 1412). This seems to be an error, however, according to the Le Strange dynasty lineage on the Le Strange Family Website. I am following their information to show Henry as a son of Robert and grandson of John. The age of Robert using the dates of birth commonly shown in genealogies matches for this relationship, with Robert being about 20 years old (born 1412) at the reported year of birth of Henry (born 1432). The Tudorplace Le Strange genealogy gives a marriage date of "abt 1434" for Roger le Strange and Jane (Joan) Beke. But the Le Strange (of Hunstanton) Website, which has no marriage date, gives the birth date for Henry as 1431. An anonymous source, with no documentation included, provides a date of 1432 for Henry's birth, still earlier than the reported marriage of his parents. The Tudorplace date for Henry's birth is also 1432. Henry Le STRANGE of Hunstanton (Sir) Born: 1432, Hunstanton, Norfolk, England Died: 25 Nov 1485, Hunstanton, Norfolk, England Father: Roger Le STRANGE of Hunstanton Mother: Jane BEKE Married: Catherine DRURY ABT 1465 -- Tudorplace, http://www.tudorplace.com.ar/STRANGE.htm#Henry Le STRANGE of Hunstanton (Sir)1 The Tudorplace site also reports the birth date of 1432 for Henry, with no comment or explanation. They have Roger's son John born in 1435 and Hamon in 1441. Clues can be gleaned from these sites, but the lack of specific documentation or discussion limits the credibility and authority of such sites. Other children of John were born in the ear of 1412-17. It does not seem likely there was a long break of 15 years, then Henry was born. Reported dates of birth for Henry match the years of marriage of Roger and Joan and their children more closely. The birth of Roger's first son John is pretty commonly reported as about 1435. Leaning towards Henry's identity as a son of Roger, rather than Roger's father John, I have estimated the birth year for Henry to be after the marriage date and birth of brother John within a year in 1435. In regard to the Tudorplace date of birth for Henry, It seems odd that a sources that reports him as the son of Roger and Joan would still report a date of birth before their marriage. This seems highly unlikely for a noble family, at least officially. Henry appears in all references to be considered a legitimate heir. We would expect the term Fitz to be included in his family name if he was illegitimate. Originally the term Fitz (as in the famous Fitzalan family) was used in its rightful meaning as Son of, comparable to the Irish-Scots Mac, Welsh Ap and the French De with father's name. The term Fitz (Germanic-Norman for "son of") came to be used to identify an illegitimate son. This practice arose because it was commonly accepted that kings and noble men would have concubines and mistresses. The formalities of monogamy required by the Roman Church were honored officially by limiting inheritance of feudal lands and titles to legitimate first sons, or lacking sons, in many cases, to the daughters in order of birth. Illegitimate sons would be given their own estates and thus the common feudal title of Lord, but with no styling of a dynastic Barony. In some cases, however, kings would bestow (or have Parliament bestow) baronies upon such a Fitzroy (son of the King) or Fitzpatrick (son of a noble) in his own right. Such a name-form is not used in sources for Henry Le Strange.
Most sources report no place of birth for Hoel. I have followed the Astill Family Tree, since all we know about his descendants is related to Norfolk. There is much legend associated with this character, and many popular genealogies have tried to associate him with Hoel V, Count of Cornouaille in Brittany. This may be so, but it appears to be an attempt to prise this historical figure into the mold of the medieval romance tale that associates Guy Le Strange with the Count of Brittany. Most sources I have seen seem to force this connection to make Hoel Le Strange the same person as Hoel V of Brittany.
Through Joan, the Barony of Strange of Knockin passes into the Stanley family when she marries George Stanley. Joan inherited the title of 9th Baroness Lady Strange Strange of Knockin. Her husband George become the 9th Lord Strange of Knockin. Their son Thomas Stanley was the 2nd Earl of Derby and became the 10th Lord Strange of Knockin.
The Tudorplace Le Strange genealogy has excellent historical detail on this John Le Strange and his relationships and his involvement in the royal affairs and changes of government in England. He was associated with Kings Richard II and Henry IV and Henry, Earl of Derby (son of John of Gaunt, who became the King of Castille through marriage). -- http://www.tudorplace.com.ar/STRANGE.htm
There is a discrepancy between the Hunstanton Le Strange Website and the Tudorplace Le Strange genealogy on the birth place of Roger and John, the children of Henry Le Strange and Catherine Drury. They agree that Robert was born in Elsing Hall (his title is Robert Le Strange of Elsing). But the Le Strange website reports Elsing Hall for the two brothers as well, and has no location for sister Ann. The Tudorplace genealogy reports different birthplaces for the three brothers, while Ann was born on the same estate as Roger, Pakenham. John is styled, in the common form related to birth estate, John Le Strange of Massingham. I am following the Tudorplace source, which has much careful detail and explanation, while the Le Strange website is spotty and inconsistent and lacks many dates and other details.
Some genealogies I have seen show Roger (born abt 1412) and Henry (born 1432) as brothers, both being sons of John (born 1387). However, the Le Strange Website genealogy, showing the lineage of the Knockin-Hunstanton family, reports that Henry is the SON of Roger. This would match the birth dates given in the other sources. At the reported birth year of Henry, Roger, son of John would be about 20. This seems to be the reasonable resolution of this. I am following the Le Strange dynasty genealogy on this and reporting Henry (born 1432) as son of Roger (born abt 1412) son of John (born 1387). It gets quite confusing tying to line out and keep straight the generations of this family, because almost every son gives almost the same names in every generation to his sons.