Sources

1) Source: Chancery: Inquisitions Post Mortem, Series I, Henry IV "Katherine, widow of Thomas Dengayne...John is dead, and Thomas died without heirs by Katherine. The right to the manor thus remained in fee simple to Joyce then wife of John de Goldyngton, Elizabeth then wife of Lawrence de Pabenham, knight, and Mary then wife of William Bernak, knight, as sisters and heirs of Thomas, and daughters and heirs of John Engayne. Katherine held it when she died...conceded their rights in these manors to Lawrence and Elizabeth Pabenham and the heirs of Elizabeth. They died leaving issue Katherine, married to Thomas de Aylesbury, so that Katherine and Thomas de Aylesbury are now the heirs...Katherine Aylesbury is aged 28 years and more."Dated: 1400. External Link
https://www.british-history.ac.uk/inquis-post-mortem/vol18/pp1-20. Reference: C 137/2/10 (Data from direct source)
2) Source: Chancery: Inquisitions Post Mortem, Series I, Henry IV "John Pabenham...All these Margery wife of Nicholas de Cryoll gave to Elizabeth de Clifford and her heirs by a fine of 1302. Elizabeth was [afterwards] the wife of John de Pabenham. They held, and had a son Thomas, who entered and held these lands as heir of Elizabeth. Lawrence Pabenham, knight, succeeded as son and heir of Thomas. He married Elizabeth Engayne and has issue Katherine wife of Thomas Aylesbury, knight, and she is still living. Elizabeth Engayne died. Lawrence then married Joan Daubeneye and had issue John Pabenham and Eleanor wife of John de Thryngham. Lawrence held the premises, and after his death John his son and heir, who died under age in the king’s ward without heirs of his body. They should therefore descend to Katherine and Eleanor, daughters of Lawrence and next heirs of John...Katherine is aged 30 years and more, Eleanor 19 years and more."Dated: 1407. External Link
https://www.british-history.ac.uk/inquis-post-mortem/vol19/pp65-84. Reference: C 137/59/61 (Data from direct source)
3) Source: The History of Parliament . External Link
http://www.historyofparliamentonline.org/volume/1386-1421/member/aylesbury-sir-thomas-1418. Reference: Aylesbury, Sir Thomas (d.1418), of Milton Keynes, Bucks (Questionable reliability of evidence)
4) Source: Privy Seal Office: Signet and other Warrants for the Privy Seal, Series I "Humfrey Stafford of Grafton, husband of Eleanor, daughter and co-heir of Thomas Aylesbury for dower of Katherine, his widow"1439. Reference: PSO 1/63/14 (Data from secondary evidence)
5) Source: Chancery: Inquisitions Post Mortem, Series I, Henry VI "Aylesbury, Katharine de, who was the wife of the late Thomas, kt: Northants, Bucks""She died on 17 July last. Lawrence Cheyne , her son and next heir, is aged 40 years and more.""Isabel, wife of Thomas Chaworth, knight , and Eleanor, wife of Humphrey Stafford of Grafton Manor, knight , daughters and next heirs of Thomas de Aylesbury , are both aged 30 years and more.""Walter was seised of this rent in demesne as of fee and he died thus seised. After his death, the rent descended successively to Philip de Aylesbury , as his son and heir, Thomas de Aylesbury , as son and heir of Philip, and John de Aylesbury , as son and heir of Thomas. They all likewise died seised in demesne as of fee. After the death of John, Thomas de Aylesbury , son and heir of John, was likewise seised in demesne as of fee"Dated: 26 July 1436. External Link
http://discovery.nationalarchives.gov.uk/details/r/C6159539. Reference: C 139/82/50. King's College London, 2014. | Mapping the Medieval Countryside [online]. Available at http://www.inquisitionspostmortem.ac.uk/view/inquisition/24-671/673 (Data from direct source)