John III Seymour
John III was born in 1450.  He died at the age of 41 in 1491.

 Elizabeth Darrell
Elizabeth was born before 1460.  She died after 1474.

 John IV Seymour
John IV was born in 1474 in Wolf Hall, Wiltshire, England.  He died at the age of 62 on December 21st, 1536.