They inherited his estates .
Barbara , daughter of Lord Edward Herbert , younger son of the second Marquess of Powis and brother of the third Marquess , married Henry Arthur Herbert , who was created Earl of Powis in 1748 .
They inherited Marquess of Powis ' estates .
Barbara , daughter of Lord Edward Herbert , younger son of the second Marquess of Powis and brother of the third Marquess , married Henry Arthur Herbert , who was created Earl of Powis in 1748 .