The birth dates of the children born to Sir Thomas Boleyn and his wife Elizabeth Howard have caused considerable controversy among historians over the centuries. It is a fact that Elizabeth was delivered of two surviving daughters (Mary and Anne) and three sons (Thomas, Henry and George), only one of whom (George) survived to adulthood. Everything else is uncertain. Even the date of Thomas’s marriage to Elizabeth is not known. Only in 1538 were parish registers systematically introduced in which all weddings, baptisms and funerals were recorded.