Richard cecil ap philip seisyll

          Born in Plas Gwyn, Pentraeth, Anglesey, Wales on Richard Cecil Ap Philip Seisyll had 1 child.

        1. His son RICHARD CECIL of Burghley (died ) married into one of the Brecknock families that had settled in Northamptonshire in his grandfather's time, was.
        2. He married Margaret Maud VAUGHAN in , in Burleigh, Gloucestershire, England, United Kingdom.
        3. Margaret Philips.
        4. Philip Cecil is the son of Thomas Seisyll and Margaret Wynston.

          5. He married Margaret Maud VAUGHAN in , in Burleigh, Gloucestershire, England, United Kingdom..

          CECIL of Allt-yr-ynys (Herefordshire), Burghley Northampton), and Hatfield, Hertfordshire

          The claim that this distinguished English political family is of Welsh origin calls for some clarification.

          The ancestral name, which appears in the family pedigrees as 'Sitsyllt' and was softened down to 'Sissild,' 'Cyssel,' 'Cecild,' and 'Cecil' in the course of the 15th and 16th century, is presumably the Welsh Seisyll; but the founder of the family, ROBERT SITSYLTT, first appears in history as a follower of the Norman Robert Fitzhamon in his conquest of the lordship of Glamorgan in the 11th century; he acquired the family seat of Allt-yr-ynys (now in Herefordshire, though the estate extends into Monmouthshire) by marriage into the family of the dispossessed Welsh owners.

          From this time on the 'Sitsyllts' generally married into Norman families and are frequently found fighting against the Welsh. Towards the end of the 15th century, however, RICHARD CECIL, the first to use the modern form