Seymour Cromwell was born in 1934.
Neither.
Jane Seymour had about 8 brothers and sisters, the most infamous being Edward Seymour, Duke of Somerset and Thomas Seymour, Baron Seymour of Sudeley. Her sisters: Elizabeth Seymour (married Gregory Cromwell - Thomas Cromwell's son) Dorothy Seymour Margery Seymour (died in teens) Her brothers: John Seymour (died young) Edward Seymour Thomas Seymour Sir Henry Seymour Anthony Seymour
Otelia Cromwell died in 1972.
Cromwell Pearce died in 1852.
Townsend Cromwell died in 1958.
Cromwell Mortimer died in 1752.
Henry Cromwell died in 1674.
Edward Seymour did in 1553 of tuberculosis
Seymour Fogel died in 1984.
Seymour Sarason died in 2010.
Seymour Hutner died in 2003.