The Dukes of Manchester

Tompsett says that the 6th Duke married the great-granddaughter of one Lieut-General Edward Pole (b.c.1733) and I can work downwards from that but no earlier ancestors. Sir Geoffrey Pole had four possibly productive sons and Sir Arthur one - one of Sir Geoffrey's grandsons (another Geoffrey) was killed in Rome as late as 1619.
There is no alternative to this: I shall have to go to the library and read Ruvigny.