Osborne Markham politician (1769–1827) Parents William Markham Sarah Goddard Children Martha Markham John Markham Siblings Frederica Murray, Countess of Mansfield Anne Katherine Markham Alicia Harrietts Markham Henrietta Sarah Markham Cecilia Markham Georgina Markham David Markham Elizabeth Katherine Markham William Markham Robert Markham John Markham George Markham Partners Martha Jervis Mary Thynne