Complex sentence: Immediately after Grey's death, much, if not all, of the estate was purchased by Edward Chapman, a director of the Bank of England, JP for Middlesex and a one time partner in the failed banking firm of Overend & Gurney.
Split into simpler sentences: Immediately after Grey's death, much, if not all, of the estate was purchased by Edward Chapman. Chapman was a director of the Bank of England, JP for Middlesex and a one time partner in the failed banking firm of Overend & Gurney.