Complex sentence: In 1739 his father, then stationed at Gibraltar, applied for the governorship of the Province of New York; he won the post in 1741 with the assistance of the Duke of Newcastle (who was his brother's brother-in-law).
Split into simpler sentences: In 1739 his father, then stationed at Gibraltar, applied for the governorship of the Province of New York. He won the post in 1741 with the assistance of the Duke of Newcastle (who was his brother's brother-in-law).