Complex sentence: The manor house, the site on which Firle Place now stands, was occupied from 1330 lived in by the Lyvett (Levett) family, who owned the manor, but was then passed on in 1440 to the Bolney family, whose daughter married William Gage.
Split into simpler sentences: The manor house, the site on which Firle Place now stands, was occupied from 1330 by the Lyvett (Levett) family, who owned the manor. In 1440 the lordship of the manor passed to the Bolney family, whose daughter married William Gage.