Complex sentence: When he arrived from York with his new wife, he found that the estate had been mortgaged to the hilt and most of the contents of the Hall had been removed, only two rooms being furnished, and what was left behind had been trashed.
Split into simpler sentences: When he arrived from York with his new wife, he found the estate had been excessively mortgaged and most of the contents of the Hall had been removed. Only two rooms remained furnished, and what was left behind had been trashed.