Complex sentence: James Laing came to own or part own also the Union and York Valley estates on Dominica, and was the uncle of William Bremner of the Aberdeen Estate coffee plantation, who married Jane Mary Laing.
Split into simpler sentences: James Laing came to own or part own also the Union and York Valley estates on Dominica. Laing was the uncle of William Bremner of the Aberdeen Estate coffee plantation, who married Jane Mary Laing.