This family name was brought to Boverton around 1560 by Roger Seys of Cowbridge who married Elizabeth Voss. She inherited Boverton land on which they built a large mansion, Boverton Place. Roger was a lawyer becoming Attorney General for the Principality of Wales under Elizabeth I. He died in 1600 and there is a wall plaque to his memory in St. Illtud’s Church. His descendants were also lawyers, the most notable of whom was Evan Seys, 1604-1685 who was MP for Glamorgan and later for Gloucester. He survived the political situations under Charles I, Oliver Cromwell, Richard Cromwell and Charles II.
Among his direct descendents is Ada Augusta Lovelace, the daughter of Lord Byron, and collaborator with Babbage on developing the ideas behind  computers.
The Seys properties at Boverton were transferred in 1774 to Robert Jones of Fonmon who had married the heiress to Boverton, Jane Seys .She died without producing an heir  and so the property reverted to him.    [See Vol.2]