(ABT 1517-ABT 1573)
+---Thomas Trethewy (-ABT 1616)
+---Bartholomew Trethewy
+---Bartholomew Trethewy (-1666)
+---Bartholomew Trethewy
+---Thomas Trethewy (ABT 1675-MAY 1743)
| +---Jane Bruart 
+---William Trethewy (ABT 1712-JAN 1777)
| | +---Phillip Mellow (ABT 1660-JAN 1711)
| +---Joan Mellow (ABT 1680-)
| +---Jane ?
+---Richard Trethewy (ABT 1753-MAR 1836)
| +---Grace Rickard
+---Richard Trethewey (ABT 1793-)
| | +---John Cundy
| | +---Solomon Cundy (ABT 1690-DEC 1759)
| | +---William Cundy (ABT 1733-)
| | | | +---David Pearce
| | | | +---Isaack Pearce (ABT 1666-)
| | | | | +---Alice ?
| | | +---Alice Pearce (ABT 1698-NOV 1739)
| | | +---Alice ?
| +---Susanna Cundy (ABT 1761-)
| +---Jane Treneman (ABT 1737-ABT 1809)
Eliza Trethewey (ABT 1823-BEF 1865)
| +---Nicholas Brokenshire
+---Elizabeth Brokenshire (ABT 1795-18 MAR 1876)
+---Ann ?