(-DEC 1948)
+---George Magnus Madison Boyle (28 NOV 1894-09 FEB 1944)
| | +---James Trethewy
| | +---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)
| | +---John Trethewy (ABT 1762-29 OCT 1844)
| | | | +---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 ?
| | +---Thomas Trethewy (ABT 1790-APR 1866)
| | | | +---William Perkin (-1688)
| | | | +---John Parkin
| | | | | +---Mary ?
| | | | +---William Parkin (ABT 1690-)
| | | | +---William Parkin (ABT 1719-1784)
| | | | | | +---Richard Morlyn (-ABT 1730)
| | | | | +---Anne Morlyn (ABT 1695-)
| | | | | | +---Nicholas Trethewy (-ABT 1680)
| | | | | +---Julyan Trethewy (ABT 1652-)
| | | | | | +---Bartholomew James (-ABT AUG 1636)
| | | | | | | +---Sicelie ? (-1608)
| | | | | +---Petronell James (-ABT 1692)
| | | | | +---Joan ?
| | | +---Elizabeth Parkin (ABT 1766-24 MAY 1848)
| | | | +---Richard Osborne (-JUN 1667)
| | | | | +---Eme Varcoe
| | | | +---Richard Osborne
| | | | | +---Joan ?
| | | | +---Richard Osborne (-NOV 1707)
| | | | | | +---Arthur Michell (-ABT 1657)
| | | | | +---Constance Michell (ABT 1635-APR 1717)
| | | | | | +---Thomas Corne (-1647)
| | | | | +---Blanche Corne
| | | | +---Benjamin Osborne (ABT 1687-NOV 1738)
| | | | | +---Bettres ?
| | | +---Elizabeth Osborne (ABT 1721-)
| | | | +---Thomas Tregenza
| | | | +---Thomas Tregenza (ABT 1633-)
| | | | | +---Julian ? (-30 APR 1665)
| | | | +---Nicholas Tregenza (ABT 1655-APR 1734)
| | | | | +---Mary ?
| | | +---Ann Tregenza (ABT 1687-)
| | +---George Trethewey (15 JUN 1843-22 SEP 1917)
| | | | +---John Columb
| | | +---Ann Columb (ABT 1811-1888)
| | | +---Elizabeth ?
| +---Bertha Trethewy (07 MAR 1870-01 JAN 1939)
| +---Alice Baldwin (ABT 1845-)
Ruth Marcella Boyle (07 MAY 1922-)
+---Minna Johanna Braun