Dyffryn House, Glamorgan; 1 the last large country manors to be built in Wales. The architectural style is vaguely Second French Empire. In 1891 the Dyffryn Estate was sold to John Cory by the then owner, a banker named Henry Ellis Collins. Cory then began construction of the present house in 1893 by architect E.A. Lansdowne . Later, Thomas Mawson, a well-known landscape architect, was commissioned to design a garden to complement the new house; landscaping began in 1894, completed in 1909.