For further details about the parentage, see H. C. G. Matthew, "Fortescue, Hugh, third Earl Fortescue (1818–1905)", Oxford Dictionary of National Biography (Oxford: Oxford University Press, 2004). Retrieved 6 June 2017; and see also, the third earl's entry in the earlier Dictionary of National Biography, 1912 supplement, by L. C. Sanders (retrieved 6 June 2017).