Sources

1) Source: Coventry of Burgate, Fordingbridge "Copy of agreement...For partition of lands of Manser Biset between John de Ripariis, John de Wotton and Ela, his wife, Hugh de Plessietis and Isabella, his wife.". External Link
https://discovery.nationalarchives.gov.uk/details/r/6fc5d8ee-c8d2-4e51-a9d6-8f63defc2030. Reference: 1M53/342 (Data from secondary evidence)
2) Source: Chancery: Inquisitions Post Mortem, Series I, Henry III "John de Plessetis alias de Plascetis, earl of Warwick...Hugh, his son, aged variously stated as 24 and more, 25 or more, and 26, is his heir." Date: 1263. External Link
https://www.british-history.ac.uk/inquis-post-mortem/vol1/pp165-171. Reference: C 132/28/13 (Data from secondary evidence)
3) Source: Chancery: Inquisitions Post Mortem, Series I, Edward I "Hugh his son, aged 25 and more, is his next heir." Date: c1291. External Link
https://discovery.nationalarchives.gov.uk/details/r/C9527783. Reference: C 133/63/21 (Data from direct source)
4) Source: The Mowbray Estate "Edmund earl of Arundel; and Sir John lord of Segrave and Christine his wife. n.d.". External Link
http://discovery.nationalarchives.gov.uk/details/r/c61f1a08-71ff-4a19-bf99-f8e99c008aac. Reference: BCM/D/5/1/9 (Data from secondary evidence)
5) Source: The Mowbray Estate Marriage settlements with respect to the marriage between Alice de Arundel and Stephen de Segrave in 1314. The marriage is arranged between Edmund Earl of Arundel (son of Richard FitzAlan) and Stephen's parents, Sir John Lord Segrave and Christine his wife.. External Link
https://discovery.nationalarchives.gov.uk/browse/r/h/f16e883c-4571-481d-a59e-99bd94affe6d. Reference: BCM/D/5/1/8 to BCM/D/5/1/13 (Data from direct source)