Complex sentence: Her husband Alexis Réaume took over the operation of the business interests but, by 1786, the firm of firm of Rashleigh and Company in London had taken over the operation of the estate.
Split into simpler sentences: Her husband Alexis Réaume took over the operation of the business interests. By 1786, the firm of firm of Rashleigh and Company in London had taken over the operation of the estate.