William Alexander Sidney Herbert, 18th Earl of Pembroke, 15th Earl of Montgomery (born 18 May 1978), inherited the title in 2003 following the death of his father, Henry Herbert, 17th Earl of Pembroke.
William Alexander Sidney Herbert, 18th Earl of Pembroke, 15th Earl of Montgomery (born 18 May 1978) is an English nobleman. He became Earl of Pembroke and Montgomery in 2003 following the death of his father, Henry Herbert, 17th Earl of Pembroke.