+---Richard Trethewy (ABT 1665-JAN 1741)
+---Richard Trethewy (ABT 1700-ABT 1764)
| +---Ann Martyn 
(ABT 1666-JUN 1738)
+---Richard Trethewy (ABT 1728-21 APR 1818)
| | +---Humphrey Harris
| | +---Gilbert Harris (ABT 1637-)
| | +---Gilbert Harris (ABT 1665-)
| | | | +---Richard Wills
| | | +---Jenifer Wills (ABT 1632-)
| | | +---Christian Best
| +---Jenifer Harris (ABT 1696-1780)
| | +---Thomas Hockin (-ABT 1607)
| | +---John Hockin
| | | +---Elizabeth ?
| | +---John Hockin
| | +---John Hockin (ABT 1616-DEC 1696)
| +---Elizabeth Hockin (ABT 1658-)
| +---Blanche ? (-ABT 1699)
+---William Trethewy (ABT 1768-)
| | +---David Warne
| | +---John Warne (ABT 1656-)
| | | | +---Henry Arthur
| | | | +---Gregory Arthur (ABT 1599-)
| | | +---Honor Arthur (ABT 1632-)
| | +---John Warne (ABT 1700-)
| | | | +---Richard Rounsevall
| | | | +---Gregory Rounsevall (ABT 1617-)
| | | | | +---Jane ?
| | | +---Jane Rounsevall (ABT 1664-)
| | | +---Mary Olver
| +---Mary Warne (ABT 1730-30 MAY 1786)
| | +---Johannes Doketon
| | +---John Doketon (BEF 1459-)
| | +---Thomas Doketon (BEF 1490-)
| | +---Richard Docton (-JAN 1571)
| | | +---Alicia Ash (BEF 1490-)
| | +---Thomas Docton (-AUG 1638)
| | | +---Thomasin Saunder
| | +---John Docton (ABT 1600-JUN 1650)
| | | +---Susanna (Susan) Babacom (-DEC 1634)
| | +---John Docton (ABT 1636-)
| | | | +---John Arundell of Lanherne
| | | | +---Thomas Arundell of Lanherne
| | | | | | +---Gerald Danet
| | | | | +---Elizabeth Danet
| | | | +---Thomas Arundell (-AFT 1620)
| | | | | +---Elizabeth Trengove of Nance
| | | +---Cecilia Arundell (-MAR 1639)
| | | +---Rachell Monp'son
| +---Honor Docton (ABT 1700-)
| | +---Thomas Tregeare
| | +---Henry Tregeare (ABT 1609-)
| +---Mary Tregeare (ABT 1655-)
| +---Mary ?
+---Richard Trethewey (01 MAR 1809-JAN 1893)
| | +---John Harper
| +---Sarah Harper (ABT 1772-)
| +---Elizabeth Cullin
+---William Trethewey (ABT 1831-BEF FEB 1879)
| +---Mary Ann Edmonds (-NOV 1831)
+---Marshall Edmonds Trethewey (OCT 1864-12 JAN 1939)
| | +---William Davies (ABT 1806-)
| +---Mary Elizabeth Davies (29 JUN 1839-)
| | +---James Searle (ABT 1763-)
| +---Dorothy (Dot) Searle (ABT 1810-BEF 1871)
| | +---Benjamin Truscott (ABT 1660-)
| | +---Alexander Truscott (ABT 1681-1759)
| | +---Lewis Truscott (ABT 1707-AUG 1780)
| | | +---Phillippa Croull (ABT 1670-JUN 1743)
| | +---Lewis Truscott (ABT 1740-23 AUG 1819)
| | | | +---John Harris (BEF 1686-)
| | | +---Ann Harris (ABT 1713-)
| | | +---Jane Paul (BEF 1686-)
| +---Elizabeth Truscott (ABT 1785-)
| +---Florence Hicks (1742-23 AUG 1819)
? Trethewey (ABT 1895-)
| +---Ralph Polkinghorne
| +---Ralph Polkinghorne (02 JUL 1697-)
| | | +---James Harrye (-ABT 1598)
| | | +---Bennett Harry alias Angarrack (ABT 1568-ABT 1624)
| | | | +---Alson ? (-ABT 1606)
| | | +---John Harry alias Angarrack (ABT 1591-ABT 1668)
| | | | +---Chesten Whita (-ABT 1652)
| | | +---Richard Harry of Angarrack (ABT 1621-ABT 1686)
| | | | | +---William Michell
| | | | +---Elizabeth Michell (-ABT 1626)
| | +---Mary Harry (1660-ABT 1733)
| | | +---Richard Wills (-ABT 1631)
| | +---Emblem Wills
| | | +---James Harrye (-ABT 1598)
| | | +---Bennett Harry alias Angarrack (ABT 1568-ABT 1624)
| | | | +---Alson ? (-ABT 1606)
| | +---Alson Harry (ABT 1601-)
| | +---Chesten Whita (-ABT 1652)
| +---Ralph Polkinghorne (ABT 1728-)
| | +---Elizabeth Richards
| +---Asdrueal Polkinghorne (05 JUL 1767-)
| | +---Christian Rodda
| +---William Polkinghorne (ABT 1802-)
| | | +---William Bartle
| | +---Elizabeth Bartle (ABT 1769-)
| | +---Sidwell Abraham
| +---James Polkinghorne (03 MAY 1833-23 OCT 1906)
| | | +---Richard Edwards (ABT 1660-)
| | | +---Nicholas Edwards (ABT 1735-SEP 1788)
| | | | +---Grace Richards (09 AUG 1697-AUG 1758)
| | | +---Nicholas Edwards (ABT 1769-)
| | | | +---Honour Moon (1743-)
| | +---Honour Edwards (27 MAY 1804-)
| | +---Margaret Langon
+---Mary Polkinghorne (15 MAY 1868-12 JAN 1939)
| +---Moses Thomas (ABT 1753-APR 1819)
| +---Edward Thomas (30 DEC 1799-)
| | +---Mary Berryman
+---Christiana Thomas (07 DEC 1834-09 OCT 1919)
+---Elizabeth Harvey