Sources

1) Source: Chancery: Inquisitions Post Mortem, Series II, and other Inquisitions, Henry VII to Charles I "John Slawghter (Slaughter), gentleman...By deed dated …., 7 Edw. IV, Roger Dreycott-on-le-moors gave the under-mentioned manors to him and Elizabeth his wife, who survives, and his heirs. He died 27 March, 1 Hen. VII. John Slawghter, aged 16 and more, is his son and heir."Dated:1486. External Link
https://www.british-history.ac.uk/inquis-post-mortem/series2-vol1/pp41-60. Reference: C 142/1/127 (Data from secondary evidence)
2) Source: Court of Chancery: Six Clerks Office: Early Proceedings, Richard II to Philip and Mary "Defendants: Gilbert Slowghtur, gentleman." Dated 1529-1532.. External Link
https://discovery.nationalarchives.gov.uk/details/r/C7477448. Reference: C 1/641/14 (Data from direct source)