Complex sentence: After Leigh's death his personal papers were deliberately destroyed by John Dodson, a Fellow of Oriel, who had been sent to Stoneleigh to sort Leigh's books, the destruction was sanctioned by Leigh's uncle and sister.
Split into simpler sentences: After Leigh's death, his personal papers were deliberately destroyed by John Dodson, a Fellow of Oriel, who had been sent to Stoneleigh to sort Leigh's books. The destruction was sanctioned by Leigh's uncle and sister.