In or before 1265 [his father] Robert Mortimer 2nd Baron Mortimer (age 40) and [his mother] Joyce Zouche Baroness Mortimer (age 24) were married.

After 14 Jul 1306 Hugh "Younger" Despencer 1st Baron Despencer (age 20) and [his future wife] Eleanor Clare Baroness Zouche Mortimer (age 13) were married. She the daughter of Gilbert "Red Earl" Clare 7th Earl Gloucester 6th Earl Hertford and Joan of Acre Countess Gloucester and Hertford (age 34). He the son of Hugh "Elder" Despencer 1st Earl Winchester (age 45) and Isabella Beauchamp Baroness Monthermer. They were third cousin once removed. He a great x 5 grandson of King Henry I "Beauclerc" England. She a granddaughter of King Edward "Longshanks" I of England.

In 1309 Guy Beauchamp 10th Earl Warwick (age 37) and [his future wife] Alice Tosny Countess Warwick (age 24) were married. She by marriage Countess Warwick. He the son of William Beauchamp 9th Earl Warwick and Maud Fitzjohn Countess Warwick. They were second cousin twice removed. She a great x 5 granddaughter of King Henry I "Beauclerc" England.

In 1316 Maurice Berkeley 7th and 2nd Baron Berkeley (age 44) and [his future sister-in-law] Isabella Clare Baroness Berkeley (age 53) were married. She the daughter of Gilbert "Red Earl" Clare 7th Earl Gloucester 6th Earl Hertford and Alice or Alix Lusignan Countess Gloucester and Hertford. They were third cousin once removed. He a great x 2 grandson of King John "Lackland" of England. She a great x 5 granddaughter of King Henry I "Beauclerc" England.

On 04 Feb 1316 Theobald Verdun 2nd Lord Verdun (age 37) and [his future sister-in-law] Elizabeth Clare Lady Verdun (age 20) were married. She by marriage Lord Verdun. She the daughter of Gilbert "Red Earl" Clare 7th Earl Gloucester 6th Earl Hertford and Joan of Acre Countess Gloucester and Hertford. They were third cousins. She a granddaughter of King Edward "Longshanks" I of England.

On 28 Apr 1317 Hugh Audley 1st Earl Gloucester (age 26) and [his future sister-in-law] Margaret Clare Countess Gloucester were married. She the daughter of Gilbert "Red Earl" Clare 7th Earl Gloucester 6th Earl Hertford and Joan of Acre Countess Gloucester and Hertford. They were half fourth cousins. He a great x 3 grandson of King Henry "Curtmantle" II of England. She a granddaughter of King Edward "Longshanks" I of England.

Before 03 May 1317 Roger Damory 1st Baron Damory and [his future sister-in-law] Elizabeth Clare Lady Verdun (age 21) were married. She the daughter of Gilbert "Red Earl" Clare 7th Earl Gloucester 6th Earl Hertford and Joan of Acre Countess Gloucester and Hertford. She a granddaughter of King Edward "Longshanks" I of England.

Before 15 Sep 1317 William Zouche 1st Baron Zouche Mortimer (age 52) and Alice Tosny Countess Warwick (age 33) were married. She a great x 5 granddaughter of King Henry I "Beauclerc" England.

After 15 Sep 1317 William Zouche 1st Baron Zouche Mortimer (age 52) and Eleanor Clare Baroness Zouche Mortimer (age 24) were married. The difference in their ages was 27 years. She the daughter of Gilbert "Red Earl" Clare 7th Earl Gloucester 6th Earl Hertford and Joan of Acre Countess Gloucester and Hertford. She a granddaughter of King Edward "Longshanks" I of England.

On 19 Apr 1319 [his step-son] Thomas Beauchamp 11th Earl Warwick (age 6) and Katherine Mortimer Countess Warwick (age 5) were married. She by marriage Countess Warwick. An arranged marriage although not clear who arranged it or whose ward Thomas Beauchamp 11th Earl Warwick (age 6) was (his father Guy Beauchamp 10th Earl Warwick had died four years before) - possibly by King Edward II of England (age 34) as a means of securing the Welsh March. The Beauchamp family established, the Mortimer family aspirational. The marriage took place after Roger Mortimer 1st Earl March (age 31) had returned from his tenure as Lord Lieutenant of Ireland and before he rebelled against King Edward II of England (age 34) in opposition to Hugh "Younger" Despencer 1st Baron Despencer (age 33). She the daughter of Roger Mortimer 1st Earl March (age 31) and Joan Geneville Baroness Mortimer 2nd Baroness Geneville (age 33). He the son of Guy Beauchamp 10th Earl Warwick and Alice Tosny Countess Warwick (age 34). They were half second cousin once removed. She a great x 4 granddaughter of King John "Lackland" of England.

On 09 Feb 1321 Richard Fitzalan 10th Earl Arundel 8th Earl Surrey (age 15) and [his step-daughter] Isabel Despencer Countess Arundel (age 9) were married at Havering atte Bower [Map]. She by marriage Countess Arundel Sussex. He the son of Edmund Fitzalan 9th Earl Arundel (age 35) and Alice Warenne Countess Arundel. They were half third cousin once removed. He a great x 5 grandson of King John "Lackland" of England. She a great granddaughter of King Edward "Longshanks" I of England.

In or before 1325 Geoffrey Saye 2nd Baron Say (age 16) and [his step-daughter] Maud Beauchamp Baroness Say (age 14) were married. She by marriage Baroness Say. She the daughter of Guy Beauchamp 10th Earl Warwick and Alice Tosny Countess Warwick (age 40).

Before 24 Mar 1335 [his step-son] Edward Despencer (age 25) and Anne Ferrers (age 36) were married. They were second cousins. He a great grandson of King Edward "Longshanks" I of England.

[his son] Alan Zouche 2nd Baron Zouche Mortimer and Eleanor Damory Baroness Zouche Mortimer were married. He the son of William Zouche 1st Baron Zouche Mortimer and Alice Tosny Countess Warwick.