Complex sentence: His maternal grandparents were Henry Pole, 1st Baron Montagu, and Jane Neville, a daughter of George Nevill, 4th Baron Bergavenny, and Margaret Fenne.
Split into simpler sentences: His maternal grandparents were Henry Pole, 1st Baron Montagu and Jane Neville. Jane was a daughter of George Nevill, 4th Baron Bergavenny and Margaret Fenne.