He was succeeded by his nephew George Murray, the son of the Duke's younger brother James Murray, 1st Baron Glenlyon (1782–1837) The baron had managed the family and ducal affairs on behalf of his older brother following their father's death.
This passage describes a change in leadership within a family structure, specifically highlighting the role of James Murray, 1st Baron Glenlyon, in managing the family and ducal affairs after the death of their father.