Whether Oxford was born in September or October 1548 to Princess Elizabeth by Thomas Seymour, or in April 1550 to Margery Golding by John de Vere, Earl of Oxford, the shadow of bastardy hung over him.
…
My own view, which determines the perspective from which I write, is that Oxford was the bastard son of Elizabeth and Seymour, the infant whom rumor declared “miserably destroyed” at birth. Throughout his life, no one knew quite how to treat Oxford. He was alternately deified and demonized, as one would expect of a hidden prince, whose presence promised a bright new future—and blew a hole in his mother’s carefully crafted myth.
— Shakespeare’s Lost Kingdom: The True History of Shakespeare and Elizabeth, Charles Beauclerk
(The author contends that Shakespeare was the Earl of Oxford and that Oxford was the bastard son of Queen Elizabeth I.)