In or before 1279 Henry Beaumont Earl Buchan was born to Louis Brienne Viscount Beaumont (age 51) and Agnes Beaumont Sarthe and Agnes Beaumont Sarthe. He a great x 3 grandson of King Henry I "Beauclerc" England.

In or before 1279 [his father] Louis Brienne Viscount Beaumont (age 51) and [his mother] Agnes Beaumont Sarthe were married. He the son of [his grandfather] John de Brienne I King Jerusalem and [his grandmother] Beregaria Ivrea. He a great x 2 grandson of King Henry "Curtmantle" II of England. She a great x 2 granddaughter of King Henry I "Beauclerc" England.

On 01 Sep 1297 [his father] Louis Brienne Viscount Beaumont (age 70) died.

In 1309 Henry Beaumont Earl Buchan (age 30) was created 1st Baron Beaumont.

Before 14 Jul 1310 Henry Beaumont Earl Buchan (age 31) and Alice Comyn Baroness Beaumont were married. She by marriage Baroness Beaumont. He by marriage Earl Buchan. He a great x 3 grandson of King Henry I "Beauclerc" England.

On 25 Dec 1317 [his son] John Beaumont 2nd Baron Beaumont was born to Henry Beaumont Earl Buchan (age 38) and [his wife] Alice Comyn Baroness Beaumont.

Around 1320 [his daughter] Elizabeth Beaumont was born to Henry Beaumont Earl Buchan (age 41) and [his wife] Alice Comyn Baroness Beaumont.

Around 1320 [his daughter] Isabel Beaumont Duchess Lancaster was born to Henry Beaumont Earl Buchan (age 41) and [his wife] Alice Comyn Baroness Beaumont.

Froissart Book 1 Chapter 12. At the last it fortuned, sir Henry Beaumont (age 47), son to the [his father] viscount Beaumont in England, entered into a barge and certain company with him, and spied this vessel and rowed after him so long that the ship wherein the king (age 42) was could not flee fast before them, but finally they were overtaken, and so brought again to the town of Bristow [Map] and delivered to the queen (age 31) and her son (age 13) as prisoners.

Before 1327 [his son-in-law] David III Strathbogie 11th Earl Atholl (age 17) and [his daughter] Katherine Beaumont Countess Atholl were married. She by marriage Countess Atholl. She the daughter of Henry Beaumont Earl Buchan (age 47) and [his wife] Alice Comyn Baroness Beaumont. He the son of David Strathbogie 10th Earl Atholl. He a great x 4 grandson of King John of England. She a great x 4 granddaughter of King Henry I "Beauclerc" England.

Around 1328 [his son-in-law] Henry of Grosmont 1st Duke Lancaster (age 18) and [his daughter] Isabel Beaumont Duchess Lancaster (age 8) were married. She the daughter of Henry Beaumont Earl Buchan (age 49) and [his wife] Alice Comyn Baroness Beaumont. He the son of Henry Plantagenet 3rd Earl of Leicester 3rd Earl Lancaster (age 47) and Maud Chaworth. They were fourth cousins. He a great grandson of King Henry III of England. She a great x 4 granddaughter of King Henry I "Beauclerc" England.

Froissart Book 1 Chapter 20. 17 Mar 1328. Then the earl marshal (age 27) and the earl of Kent (age 26), the king's uncle, made a peace between the king (age 15) and the earl of Lancaster (age 47), on whose part was sir Henry lord Beaumont (age 49), sir Fulke Fitz-Warin (age 43), sir Thomas Rocelin, sir William Trussel (age 48), sir Thomas Wither and about a hundred knights, who were all expelled out of England by the counsel of queen Isabel and the earl Mortimer: for he was so covetous, that he thought to have the most part of all their lands into his own hands, as it is more plainly shewed in the English chronicle, the which I pass over and follow mine author.

On 06 Nov 1330 [his son] John Beaumont 2nd Baron Beaumont (age 12) and [his daughter-in-law] Eleanor Plantagenet Countess Arundel and Surrey (age 12) were married. She the daughter of Henry Plantagenet 3rd Earl of Leicester 3rd Earl Lancaster (age 49) and Maud Chaworth. He the son of Henry Beaumont Earl Buchan (age 51) and [his wife] Alice Comyn Baroness Beaumont. They were fourth cousins. He a great x 4 grandson of King Henry I "Beauclerc" England. She a great granddaughter of King Henry III of England.

On 10 Mar 1340 Henry Beaumont Earl Buchan (age 61) died at Buchan. His son [his son] John Beaumont 2nd Baron Beaumont (age 22) succeeded 2nd Baron Beaumont. [his daughter-in-law] Eleanor Plantagenet Countess Arundel and Surrey (age 21) by marriage Baroness Beaumont.

[his daughter] Katherine Beaumont Countess Atholl was born to Henry Beaumont Earl Buchan and Alice Comyn Baroness Beaumont.

[his daughter] Joan Beaumont was born to Henry Beaumont Earl Buchan and Alice Comyn Baroness Beaumont.